Yes, doing your first portfolio page can be a little bit overwhelming at first. A course that really helped me was on udacity.com was their Intro to HTML and CSS course. Not only do they go over the mechanic of making a website, but they also have some great tips on planning the design, such as drawing out what you want your website to look like and then dividing it into boxes. They also have an entire section devoted to Bootstrap.
Oh, and don’t feel like you have to use Bootstrap. I decided not to use it in making mine.