I have an associates degree from the Art Institute of Pittsburgh, not that you need any type of degree with Graphics design it will put you one step ahead of someone who doesn't when trying to get a job.
There is a lot to be learned. This link below has a few of the classes that I took my first year, and many others that you would need to learn and remember.
50 Totally Free Lessons in Graphic Design Theory
http://design.tutsplus.com/articles/50-totally-free-lessons-in-graphic-design-theory--psd-2916
Also, learning to code in basic languages and have the skills of a graphic designer and there is no limit to what you can achieve, from web design/app design leaving you many options in the job fields. Once you are a master of all of this you can make 30k-100k a year, depending on your experience, level of knowledge and skill.