Hi Taylor,
As many of the developers above told you, 3 months is a lot of your time for(on the end) a Shopify web-site, I assume you are aware that Shopify will not raise your developer skills at all, it’s practically data filling CMS system for newcomers grannies and wifes and 1st web project to start with is just like a 13 years old kid who is trying to understand how e-Commerce works in general.
I suggest you to listen to a “Oxyrus’s” short but concise advice and would like to add again “Shoppify project is something you will never wanna show to your future clients or use as a portfolio starting ground because in 3 months from now, you will probably be ashame you ever thought to advertise yourself that way(grandma’s & kids toys CMS’s that generally never give you full development control of your shop)”. Sometimes it’s a price range, sometimes client asks for a custom parameters to add to their shop products like color, material, basic dimensions(width, height and this has no end… solutions like that will be a pain in the ass and not a developer friendly solutions alike). Small stuff like clients wishes to move some CSS or stylize it some (only they know why that should look as they want) way that is just not going to work by any chance, things that are fundamental for your developer’s freedom and code or style customization, some aka. lot’s of basic stuff will just be impossible and you will come down to a 4 months spent on some guy’s demands and crazy ideas, most of the time it’s their 1st website/e-Commerce shop ever but they will try to convince you they heard from some guy that things are better that(nonsense CSS, colors like it’s 1995, some old and god forbid jQuery anim. effects etc.) way which often isn’t user friendly or guy just heard menu should be bottom only, top slider all over the place big as a Big Mac but that’s just a clueless client who is using your talent and much more important to me “your expensive time, hours, days and months” for free, changing their opinion every week and by the time you think you are done, he just heard he needs to change a complete CMS or framework, technology used for project or a server type.
I do develop websites, web-apps and e-Commerce solutions and already have experience in that field, when my client asks for a solution, I speak with them open minded, try to give best advice for a shop/app/site that will fit their needs best at the given moment,
Sory for a long text I just realised it’s too big for this kind of advice and probably a lot for you to digest but I would go from star, like:
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checking basic parameters as(for e-Commerce shop website)
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getting the approximate amount of the products that will be sold in the solution(for me one of the most important thing when it comes to solution/framework or CMS choosing to start and build with it).
For example: **CMS/Framework Battle aka. what solution will work best for specific shop scenario that my client needs(**happens after you hear out your client needs/demands and workaround shop workflow with daily routines(500-1000 purchases, 1000-1500 products, 300 categories 3000-5000 optimized images for products) and before you start the development). Would not suggest to go with Wordpress or Joomla or CMS that are not genuinely made for e-Commerce because of the naiveness, and I usually compare it as a child vs. experienced marathon runner grandpa who does all the job for you much safer already, has a enormous payment gateways/solutions integrated already or are able to integrate within 1min. of your time and start to generate cash for your satisfied client instantly because I always want a good documented framework so I will be comfortable to adopt addons and upgrade it in future, whenever my client asks for any kind of a customization/addon/plugin or whatever the fuzz is. It just runs better and client is more than satisfied and willing to recommend you for more e-Commerce development work in this field.
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Shop with 5 products or shop with 1 product in 100 variants, colors, dimensions and price ranges is a completely differently behavior against your Database’s(sry for my Eng. but it’s important for me thast you understand the logic of it from start - solution choosing and why would you go with that one particularly and ot with some other similar open-source CMS or paid CMS or whatever, decision in start makes your life and project easier for your future development of it and that’s why I try to pick the best for that type of shop).
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You have 5 products shop that will never go up, expand, grow or be able to add more because your client has 5 things he wanna sell end of the story. That scenario is more than typical for small business companies nowadays and you don’t need Magento to be able to create and finish project in 3 days, you probably wanna use some lighter framework or CMS like PrestaShop or some of your choice because it’s just too small to spin on something that you never going to use 5% of the CMS possibilities so just keep it simple and clean from here. Another solution of course is a 5000-10000 or more products shop like a big time seller-reseller wher you can buy from needle to lokomotive practically and that is much more serious because your Database will act completely different, in many cases slower and server dependant than a 5, 10 or a 100 products shop. this big scale stuff is best managable and made by above mentioned Magento CMS that uses PHP Zend Framework to steam with and has some kind of it’s own template language as any other CMS but also a lots of options for a big-scale shops with a large amount of stuff inside/ Also covers a solid design, theming, CMS is developer friendly, you can edit absolutely anything you want because of it’s open-source’s nature etc. so classic case is: small projects with good security, lots of plugins, good community and documentation - PRESTASHOP. And for big scale shops with all the rest same as above = Magento CE(CE stands for Community Edition which is free, customizable, just the way we want it to be when our client asks for customization - we accomplish it in hours not months even for a mid-range projects where I have my own assessment but usually go with PrestaShop when I count product-wise functionality up to 3-5k of products, for anything above it goes fine but stutters on lot’s of servers, don’t load fast like it loads with 100-500 products shop etc. there is infinite number of parameters to go with this but my answer is too long and I want you to be able to digest it very easy, so I will end this solution battle here).
I can also get you started if you go for any of this solutions and help over Skype whenever I have time for it ofc. just let me know if you need it because my personal opinion is that you already lost 3 or more months of your life and trust me with Shopify you don’t improve your programming/development skills, thinking skills or a solution bringing conclusions. It just is what it is, a paid service with pre-configured 95% of things with few options and themes that go crazy on iPhone 5 or some tablet which is the best selling in the country of your client(Shopify don’t know the model and display size so media width is not even there and guy stays out of business before even starting a shop advertizement and so on and so bad for you to begin with), small room of freedom for a developer, which is a killing bottleneck for e-Commerce stuff.
Conclusion: You as a freelancer who does free e-Commerce solution for some non-serious guy who changes opinion on every aspect of his shop whenever Novak Djokovic wins a match… bro he would not even have opinion on anything if he wants my “free” time, when i’m able to help him as a human being so practically speak with a guy and explain him the situation, rework the future plans of the shop and tell him your hands will be almost cuffed for a large number of his demands if goes with solutions like “boys with plastic toys” Shopify.
So listen to above comment made by fellow colleagues @Oxyrus & @jamesperrin start building new concept, choose serious stuff that goes like a breeze = less of a headache for you, much satisfied than Shopify idea he will be very soon. Accomplish and respect yourself and your time, specially free-ride type of projects, show him your thinking ahead Yoda advised jedy knowledge and same time invest in yourself by not wasting another 3 months and not learn a thing if you plan to do this for your breadcrumbs soon.
Any comment from a community is welcome of course, add, agree or disagree with me - I will reply in a timely manner and help you or anyone with similar problems/choices you make in a situations like this.
Before you go, respect yourself and your time above all, try to learn some/any new skill from a project you are on, improve and it will payoff even if you live in Zimbabve, don’t pay attention to local not helping you or playing deff for any questions you might have, community here is much bigger, better and important for your carrier than some guy from your neighborhood who is shaking because he heard some new guy is taking over all his Shopify clients and redesigning from scratch in a standalone independent e-Commerce environments and why I still did not move from Shopify or similar all-in-one, one-click-install bag and tag headache solutions out there on the web.
Useful links, documentation is one of the best in this field for those 2 solutions(if anyone disagrees jus’t point out 2 CMS which can parry to this 2 guys I gladly recommended to our Taylor here 
Give it a try, download, if you have Xampp, Wamp, Mamp, installs and configures in 2-5mins depends of your preferences.
PrestaShop 1.7 - Latest version
Magento Community Edition
again sorry to you all for the long run but someone needed to take 10mins and explain basic stuff in more than 3 lines, not all of us are looking in the same direction, some are just taking advices that has no sense and waste time because they listened to a bad advice on “some” forum or blog.
READ DOCUMENTATION, SEE WHAT THEY ARE CAPABLE OF, EXPLAIN THE DIFFERENCE TO YOUR CLIENT, FINISH YOUR PROJECT IN 2-3 DAYS FROM TODAY, LEARN VALUABLE NEW STUFF, IMPROVE SKILL OVER TIME AND WRITE CODE AS MUCH AS YOU CAN EVERY DAY, NEVER LOSE THE ROUTINE AND YOU ARE A HAPY PANDA VERY SOON 
Best regards Taylor and I hope you will adopt some of this and build your carrier with right tools for right job in the future and never waste a single day for free-riders that don’t know what they want next week, it’s your time, you decide how you donate it to him, just make sure it benefits you as well by learning something new every day, especially on free projects like you develop at the moment. For any other thing just ask here or send over your Skype or email and I will be glad to help you out to get started and think forward when e-Commerce is your choice. Tripples the showcase website or any presentation-type website in earnings, Magento even 5x and I don’t see it will go down in the near future tnx to the communities they have, cheers and hope to hear from you.
edit: the amount of text is bigger than my essay written 15-yrs ago in high-school I swear but amount of injustice for guys like his client free-ride-no-opinion-what-I-want-this-week-need-to-change-top-menu-to-rose-yello-combination-my-good-friend-who-owns-zero-e-Commerce-solutions-advized me to go change it next week hmmm hey Taylor before we open, can we just make small changes, let’s change every single thing or even make a new shop in more fancy colours, sidebar from left to right, menu from top to bottom, no delete the menu… GET OUT OF HERE PARASITE CLIENT GUY !!! LET TAYLOR DO SOMETHING IN NEXT MONTH NOT INVOLVING YOUR EPIC IDEAS ABOUT e-Commerce, or solutions for it, or a menu position or a sidebar side if present - you know why? Because it’s free of charge and I know this better than you my dear client.