Birth Control

Hi! I'm 15 and I just got this app because my cycle is always difficult to keep track of! But I found this board and everyone is so supportive here! 
Oh anyway! In regard to the topic, I'd like to know if I should take some. I'm not sexually active and don't plan to be for a few years. But I've heard it's good for other things that are not preventing pregnancy. I'd like to know what those things are, and see if I should try them. Could anyone explain?