As someone who's just your average guy part of the car scene in Ontario. It really helps if you're already a a car enthusiast and make your connections by meeting people through car meets. I'll tell you first hand, theres always people looking for someone to take photos of their shit boxes maybe not the BDE sponsored kinda guys that already have a following. If you're not confident in your skill as a photographer, offer the pictures for free. Chances are guys love it regardless of how it looks when people take pictures of their cars because it strokes their ego's. Car meets are the best place to take pictures of cars. Invest in some equipment and go out there shooting. But honestly key is put yourself out there and network. I'm fortunate enough to have have multiple close friends built from talking to people at the car scene. Maybe not in the same boat as you, but I picked up photography again after I crashed my rice burner. As far as education, I dunno personally I'm winging it, luckily my friends are pretty hype about me getting new camera gear and their always down to take photos, so going out with them gives me good practice on framing my shots better and getting better composition, I'm also fortunate enough to know, and be friends with some of Ontario's local car scene photographers, so getting pointers from them is always helpful. I'm just hoping you live in an area with a pretty active car scene.
Pic related is a bunch of my buddies cars, went out there to go practice. Hopefully with the better camera, but more specifically lens I'm hoping to not be limited I the things I want to do. Low light is very difficult on a 16 year old camera with a lens that was designed specifically for macro. Composition definitely could use a lot of work as well.