Hello everyone! I'm new to the threadless scene and am having trouble understanding the whole process.

I downloaded the Adobe Illustrator free trial to see if i could get used to the program before i bought it. So far I've proven myself to be incapable of even coloring in a square haha. Does everyone who submits designs seriously figure out how to use it??? I draw and paint free hand very well.. I'd hate to be limited by a computer program. How does everyone else do it?