I am not only doing this to impress colleges (although that’s part of it), I have a genuine interest in economics and plan to major in economics in college.
Also how much time does it take to self study one of these courses? From my understanding they are half year courses and only take up a semester usually. However, I am not sure as my school does not offer AP Econ.
If you are interested in Economics, then take both exams. Macro has a bit more math, while Micro is a lot more theory. Both inclde graphs (which are really important). Honestly, they take no more than two weeks (one for micro and one for macro).