First i would focus on quality foods. The usual stuff protein(chicken,steak,turkey,eggs) quality carbs and healthy fats and don't be afraid to cheat once and a while. The only supps that are worthwhile IMO are whey,creatine,multis and efa's. Eat every three hours or so.
Also if by "A school" you mean college, please don't be one of those guys that when all your friends are going out to party you're sitting there weighing chicken breasts and writing in your log book. Working out and eating good is great but don't let it control your life,be dedicated but have some perspective. Just my.002