Focus On Education

What are good business ideas for my class?

I have to create a business plan for one of my classes in college. We have to run our own business and it can be almost anything. The exceptions are sit down restaurants, dorm cleaning and transportation. Many people have done easy things like balloon delivery on birthdays or a bagel shop. What are some other ideas? Thanks for the help!
Thanks for the ideas but im going to need something more realistic for 6 college students in 2 months.

Dollar store.