How do you find local legit events?

I’m thinking of starting either a small coffee cart or craft goods booth. I don’t even know where to find events to sign up for.

How did you find the events you signup for? How do you know if an event is legit and not a waste of time? Is there a website for mobile vendors? Are there permits, licenses or other paperwork I need to get started?

Thank you 🙏🏽