As a fellow new coder I understand your confusion. I have been studying web development and coding for about 8 months and working through Free Code Camp since January this year. I would definitely agree with Goethe_AJ that what you have learned is sufficient. However, you should check out the documentation (follow the link Owel gave you) for bootstrap. You can skim it to get an idea of how everything in there works and what you would like to use in your project.
Bootstrap is a really fun simple way to style HTML without much time or effort. For example Jumbotron is a container you could use to showcase splashy eye-catching content at the top of your page like your main header and first photograph (If I am misrepresenting it let me know). If you already have some content you want to showcase at the top of the page you could add
after your content you want to showcase. Much of the time that is all there is to utilizing Bootstrap in you project.
Don’t be discouraged! These are challenges so they can feel frustrating to everyone.
My general advice is 2 things. 1 never be afraid to keep your projects very lean and basic. 2 keep using this forum. While often you can find the answer out there on the internet, sometimes you don’t know what piece of information you are missing and that means you probably don’t know how to find the answer. Talking to people on this forum can help in those circumstances.
Hope this helps.