It depends on whether you want to try and go straight into featured work.
Mad Dog and Casting Collective are both good for getting background extra work - which might be just being one of a crowd in a brief music video shot, or something much more.
One lad I was working with on a current Warner Brothers film was booked as an extra (along with 300+ other extras) but the production team liked his look and he ended up with a credited role. That was on his first ever production with no acting training or experience.
A lot of it is about being in the right place at the right time, work as a background extra etc can at least help with the right place part of it...
I think to do stunt stuff you have to be a qualified stunt person and be part of their union/ association. You need more than one skill driving being one of them. I think you need something like 4 out of 6. I can do fight stuff and have some film training but can't call myself a stunt person.Other things are fighting ,jumping from heights, swimming, diving. You might find some driving stuff, I have done some extra fighting stuff, but might be worth looking into proper stunt training.