One of the best classes I had in college was Art History. It did more for my photography than the couple of photo classes offered by the school I attended. The public, and often patrons and academics decide, what's art and what's not. Unless you take the Jeff Koons path (art by formula), you have to be you. Nothing short of that. Pollack said "The best painters paint themselves". You can't worry about "art". Concentrate on learning to know what you like and don't like, for whatever reason. And, make stuff you like. You can't worry about approval unless doing paid work. Then someone other than you has a right to input and decision.
I think the most important thing I've learned is what I like and why. It gives me direction. It helps me decide about light, subject, weather, light modifiers, project specific film or digital.. all that. I know I like tomatoes on my fish sandwich. Look at a lot of art. If you can't go to galleries and museums. The web is full of hood art. Art sites aren't like photo sites..no one is uploading 3000 pictures of their vacation.
Vermeer knew a lot about light, if that's any help..
pkr