When I was about 14, I had an opportunity to learn from one of, if not the best bodymen I have ever known. We worked in his garage at night and weekends. It was a long time ago, as the minimum wage was $1.25/hr. My friends worked at different types of jobs making about $30.00/week and I was making about $100-$150/week. I started out just sanding and other little things while I watched and learned. That was about 34 years ago. The proceedures and cars have changed some over the years. The basic principals have not. That great friend died a year ago. What I learned from him will be with me for as long as I live, and it was much more than just doing bodywork and auto repair.
Although a good bodyman in a busy shop can make a good living, many still do work on the side. If you can find one that does, maybe you can work out a deal with them to help them while you learn the basics. Everyone gains by that deal.