How do caricature artists at the beach (pier) get a permit to work there?

I'm a caricature artist and I've seen some artists (sculptors, face painters, name painters..etc.) working at like the Santa Monica Pier. I'm trying to see if I can work as a caricature artist in the San Pedro beach area..where the restaurants are at. But I can't seem to find any info on google..I just find articles for people who don't live here looking to get a work permit. I already have a work permit! hahaha I need a permit/license to draw and sell caricatures at the beach/pier. I guess you could call it a vendor's license? idk...any help?!