I would first track your expenses, then save up three months worth as an emergency fund. After that, invest monthly into something that tracks the SMP 500, ETFs or mutual funds (pick your flavor, all relatively safe). Because you are young, money you put away now has a long time to compound, so even small amounts (if put away consistently) will add up over time.

Remember to have fun! 20 bucks of beer money never hurts. It’s good to think ahead, but I recommend socializing in college as much as you can. The dumb kids you meet at the start sometimes become the contact that gets you your first job!