How to edit specific parts of profile???

I'm currently try to edit my profile and there's something I'm stuck on:

One of the codes I added makes the navigation links all white, which mean the ones on white backgrounds aren't visible. I was wondering what are the codes for specific section of your profile? (for example, profile. blurbs. heading. and all that bc I don't know what they're all called so I can't edit them the way I like.

I hope I can get some help pls!