Hello @kwinfl, welcome to freeCodeCamp forums!
If I remember correctly it does cover some of what your asking, however it doesn’t really focus on these too much due to a few reasons, mainly related to how the curriculum is setup. For example its hard to test external style sheets without a full dev environment, which fCC doesn’t go over so its easier to learn the core concepts, at the cost of learning how to setup your own local dev environment. So the limitations of the platform means it can’t directly “teach/test” against these things.
The other consideration is that freeCodeCamp curriculum isn’t a one stop shop. It focuses on some things, but doesn’t try to cover everything. Using external resources like freeCodeCamps youtube channel or searching the news feed or even leveraging these forums to get help/answers/feedback. All of which are all part of freeCodeCamp, but aren’t directly tied to the curriculum
Good luck, keep building, keep learning