I'm thinking of becoming a crime-fighting Vigilante...

The title kind of sets the ground for this. Basically I watched Kick-Ass one too many times and I'm feeling strongly compelled to go out at night and try to stop muggers. Besides the initial idiocy of my idea and the obvious lack of training I have, I still want to give it a try. Don't worry I'm not going to try and save america, folks.

Does anyone have some suggestions on what might be useful skills to have? Obviously a martial art of some kind, but what would be a good kind to learn? Any ideas on what I should start off doing? Armor choices (I've been thinking of using a motorcycle suit)?

TL;DR : What do you honestly think might help?