Purely for what it’s worth, I recommend getting familiar with Inkscape (or another vector-based illustration program) if you’re going to be doing graphic design such as logos, signs, etc. That’s not to minimize GIMP, it’s just that Inkscape is more designed for that kind of work. GIMP, on the other hand, is vastly better at painting, photo retouching and so forth. Of course, both can be used for their respective strengths on a single project, including (e.g.) Scribus for page layout.
Just a suggestion…