Must say AP classes aren't all that hard, i could see how it could make you a bit nervous at first, believe me i was, but once you see how it runs you'll be glad you did it, i sure am. But be prepared to STUDY, thats where i got killed, i'm not the top of my class but i sure am not stupid, study and make sure you have some time you can devote to studying, i participate in sports year round, football, track, lacrosse and i just needed to find a time to study.
Classes also move fast, not hard at all to keep up, just make sure you're on top of your work and don't miss too much school, that will put you behind and it could be difficult to catch back up, by missing too much i mean like 3-4 days in a row, a day here or there isn't going to kill you.
Good luck, you'll have a blast, i sure am.
"Obviously you're not a golfer.