There isn't a degree for detailing as far as I know. There are some organizations that love to take your money to teach you some fairly advanced things, but you have to go in with a fundamental knowledge of the industry first. You can learn important things like touch up paint, paintless dent removal, window tinting, and other things like that from local shops which add a lot of value to your detailing business.
The only universtity for detailers is the University of Hard Knocks, unfortunately. There are a few of us who have put together guides and videos on how to detail properly, but that is pretty much all there is out there short of just getting in and getting it done.