I called my local police station (you might have to call your county clerk, police station, or a lawyer that knows performance laws in your area) They said in a public place you need a license if you are going to take money or have a group of people performing. If you are on private property (which is any property owned by a business that isn't run by the city, county, or state) it is up to the property owner to decide on what is allowed and isn't.
Your best bet is call someone that knows the info for your area, court clerk might be a good place to start, and if you are performing at a shopping center then call the owner of the shopping center and get permission and find out what they'll allow (filming, take tips, etc.) they may have you sign a waver or something.
Better ask someone before hand so you don't get in trouble