I have it downloaded, and I don't have much experience with gfx at all.
Just looking to have something to mess around with on the comp, to be honest, nothing too serious.

Is gimp a pretty good program to learn on?

It's a photo editing software. Some other software might be more user friendly to certain people and then other people might find GIMP more user friendly. It's fine for what it is a photo editing software. People will suggest you use Photoshop since it's the mainstream photo editing software but even amazing things can be pumped out of things like MS Paint. The program won't make you great only you can do that.