There’s really no longer any kind of gatekeeping preventing people from just being a clown. The proof is in the pudding, you are a clown if you can do all the things a professional clown can do. Now turning it into a career you can pay rent with is the real challenging aspect, which is true of most performing arts.

My wife is in a professional dance company that focuses on aerial dance, and has performed around professional clowns in the past. If you want to just busk you don’t need anything but skills, but if you want to perform on stage or tour you will need to hook up with some kind of performing arts company or an artist co-op.