There are grooming schools throughout the country. One popular place is Nash Academy. I think they have a few locations (we have a member that would know more about this). If I remember right, there is one in NJ and another in the KY/TN area. You could check their site.
You could go to grooming school and get a degree. It's really all in what you want to do with your life and what you enjoy studying.
Staring with a few classes at a local school to see what ends up being of interest to you may not be a bad idea.
My choice out of those would definitely be a dietician, but that doesn't help you any.
And I would go close to home unless I could take my dog with me.