tablets are a real bitch on the first day, I can tell you that. I can already tell that you're gonna get way better, though.
and layers! they make errything so much easier, from backgrounds to colors. (a.k.a: carl's lineart. under that, his colors. under that, background lineart. under that, background colors!)
When you use layers, you won't screw up lines when making/fixing colors, and you won't have to forget up the foreground when making/fixing the background. the concept may be a tad tough to grasp at first, as I only started using them like 2 years ago, even though I started digital artin' when I was around 10.