I was wondering if I could gather people up outside of walmart and have a eating contest and record it
Only if you get permission from the store - and the store is probably going to want a monetary fee before they will grant permission.
You'll definitely need permission. Each store generally has someone in customer service or front-end management that is designated to screen requests like this. As for monetary compensation, that will likely depend on the purpose of the contest. Does it benefit a charity or anything?
