So is the best thing to learn how to make navigation bars that are responsive and overall how to make the webpage responsve? What otehr things should I learn if I’m trying to get a job in 5 months?
As far as getting a job in 5 months, that may be a bit optimistic. While it is possible, it would not be consistent with most people’s experience. Of course a lot of this will depend on where you live, how good you are, how well you interview, what you’re shooting for, and also luck. I’m not trying to discourage you, but I also don’t want you to feel like a failure if you can’t meet what I feel might be unrealistic goals. I had a little programming experience (a little from years ago in a different language), a few programming classes way back when, and it took me two years of working my ass off. ymmv
Now, as to Bootstrap. I would look through the docs and see what else interests you. But I also wouldn’t get too bogged down. First of all, things like flexbox and CSS grid have made Bootstrap less important. I think it’s good to learn the basics of things like Bootstrap and jQuery, changes in JS and CSS have made them less relevant, and they are slowly being taken over by SPA libraries like React, Angular, or Vue. Of course, you can use Bootstrap with React (maybe the others, idk) but it is less relevant.
I would also warn against the “100% understanding” goal. I think you would be better served by learning 30-50% of each and move on to the next thing. There are soooooo many things to learn. Really, you have no idea. I would recommend moving through the FCC front end and libraries sections and then chose a front end library. FCC teaches React which is a good choice. Get to know that library really well, build lots of things in that library and it’s supporting libraries (redux, thunk, sagas, react-router, etc). I think really knowing that well would serve you well.
Then, while you are learning that, start on the backend section. (FCC teaches Node, which is as good a choice as any and might be easier because it uses JS). It takes a little learning (but not much) beyond what FCC is teaching, but you can use your React for the front end for your fullstack projects.
At that point you have a full stack which greatly increases your odds of getting hired. That’s the goal, just keep learning, keep building, and eventually the combination of your increasing employability and luck will intersect and get you that job.
I might also suggest looking for jobs in your area. If they are all demanding experience in Bootstrap, then go for it. My experience is that it is not demanded much. But that may be jaded by me looking primarily for React and React Native jobs.