It's important to get stuff that lasts a long time. Make sure all your dried foodstuffs are stored in airtight containers. If it's spoiling or getting infested that's wasted money.

Stuff I bought while in college: dried soup (the cheap Mrs Grass crap) or Rice-a-Roni can be stretched by adding extra egg noodles/rice. And enhanced with meat/frozen veggies. Hamburger Helper, but only when on sale.

Buy meat in family packs, freeze it for use later.

Those little refrigerated tubes of dinner rolls are so versatile. Butter them and sprinkle with garlic salt before baking for garlic bread. Butter and cinnamon sugar for dessert. Marinara sauce/cheese for tiny pizzas.

Kool-aid instead of soda.

Pasta dishes. Spaghetti, macaroni, noodles. A pot of macaroni with just a can of diced tomatoes can be really satisfying. A pot of rice with just tomato sauce.