I’d try the “community learning” (used to be callled adult ed) classes offered by local school districts. Those are open to teens and adults and have a variety of short-term (1 to 2 session) classes, which I think this fits into.
Good luck!

I know this is a random question, but does anyone know of a spray painting class/workshop for teens, where they can go home with a canvas or posterboard with their artwork? Thanks.