I am no idiot, but to get started in this hobby do we need some kind of license or membership that requires money? I just want to know so I don't make any mistakes.
I would start by finding locals. You will eventually need a NAMBA membership, which you can always get a one day for starting out. Depending on the combat style you battle, you may need another membership, like if you wanted to battle IRCWCC Fast gun, you would also need a membership there. Your profile says you are in Minnesota, I would get with the Port Polar Bear guys and see what warship combat is all about, before anything else.
