Most gyms won't do that. Go try a place out if you like it stay if you don't leave. Bjj will definetly help your self defense and it can also hurt you on the street. The best thing to do on the street is walk away if you can. It can help you if your taken down and also help if you need to take someone down and control them on the ground. I'd be real careful about taking someone down if you got into it on a street corner. You never know if he has friends with him that are going to be willing to deliver their shoes to your head if your controlling him on the ground.