Learn a couple of cheerleading routines , be flexible , make sure you are going to be able to support some weight . More likely when they do the pyramids or raise some one up in the air you'll be at the bottom . Have positive energy. And be healthy
Go for it. I've been doing it for a year and a half and I love it. I did gymnastics prior to it.
As for the name calling, it may happen (it did for me....a lot) and you just have to get over it...especially when you're at a game, you don't have much of an option.
To prepare: Stretch a lot. Practice chants with movements and do routines (if any are applicable).
your high school would probably hold an empathy seminar for you if I said you shouldn't do it lol. but the fact remains; it's generally a female dominated "sport" because, most sports fans are straight males, and sex sells. I would personally suggest that if you wanted to spare yourself the mental grief, maybe avoid going public with it if your not fully comfortable with being judged unjustly for doing something you enjoy, and just do it at home in a safe environment. but that's just the unbiased way of looking at it. if you still really want to, hey man go for it lol
Go for it, dude.... :-\