Learning how to do body work?

I've always wanted to learn how myself. I did my engine bay but there wasn;t any damage to repair. Just prep work.

I havnt the space or time but would like to get a old hood, door, etc... off a car and "practice" on it. Take a hammer, make a dent , and try to fix it. lol

I learn stuff it seems better by doing it and learning the hard way I guess.