I don’t believe food swaps fall under any regulation, since there is no money trading hands and people aren’t engaging in commerce. California has some extremely strict rules, but I know that food swaps happen in the Bay Area all the time and I haven’t heard of one getting shut down. I assume it would be less strict in MD.
However, the food swaps I’ve heard of are purely volunteer events, and it sounds like you’re trying to collect money from people to setup there, so you’d essentially be a market, I think. If you are collecting money from people for the space, then you’d probably need to talk to some dept, and there may be a license for you to get.