It really isn't hard I suppose, but don't get in the habit of doing it in college, because that's when you start slipping. Anyways you don't need make up at all. You'll probably have to go to school for a little bit though, since you're 13 it's going to be hard to get home, unless you can walk. Since you can't call in because you're not an adult you have to actually to go school and fake being sick: look real down, hold your stomach and if you really want to do it right make yourself throw up, you can rub your eyes a lot to make them red too. At any rate it's possible, but the getting home part is hard unless the office will allow you to go home. Have fun.EDIT: Also try not eating and make yourself hungry, it helps to act when your stomach is growling.
