You need to check with your local health department for the answer to that.
In my area, anything that results in food being prepared and temperatures monitored requires a health permit. If I served only packaged items, I would not need this.
I do get a break on my permit, being that I'm a drive-in. I get a seasonal discount (50%) off what a full-time kitchen would pay.
Depending on your menu, your concession staff may also need health cards. The test is pretty simple... stuff about how to handle food correctly, tie your hair back, what temperatures to cook and hold food, how to cool foods for storage... and how often to wash your hands... that kind of stuff.