Graphic artist...doesn't that mean that you have to be good at drawing first of all?
I'm not much into graphic design, but I believe that some background knowledge like
color compatibility, etc., should come first, and practical skills like Photoshop (yes, that's obvious - it is essential to have a good command of it) - later.
I know, that best coders are those who studied coding systematically, so I suppose that approach is applicable to all work spheres. But I do not insist upon that blueprint of becoming a designer, I just believe in it