Some awesome ones from the DanielGarciaProject
Joe Blow
Quarters
Rubber Made
Chi
Loops are also a good idea. I would sugest money stuff. Quarters are always useful.
An excellent thought would be pickpocket magic, jack all is needed for that.
Mentalist stuff is good, but it takes a LOT of practice, and confidense, which, being in school, would make any trick harder, trying to accomplish mentalism would leave you dead in the water.
Also One of my personal favorites is to write things on paper and put the paper in there pockets. It's not really magic, but really fun to do, gets you into all sorts of hilarious situations. I also like to get into peoples lockers, by what ever means necessary for example, they leave it open, or you know there combo, take all there stuff and put it in someone elses, or an empty locker somewhere, im sure your school has tons. leave the person clues as to where the stuff might be, like single numbers, and in the wrong order.
Fun stuff makes for interesting times.
One other thing to think about, if you guess something, and your wrong, people will easily forget, but if you guess something, and your right, it will stick with them, so practice just guessing ****, and you'll get better and choosing the right stuff. Gives a really cool impression of you.
rather off topic by the end of this, but just some cool stuff to think about while you're going through the motions of school... which can be a real dragggg........