Well, to your credit, I've seen a lot worse, too. Art is one of those things you've gotta really work at over time, and even artists you think are really good will probably be putting out much better stuff in a year. So don't give up hope, and don't feel too bad about what you're putting out now, even if there's room for improvement.
I'm probably not the best for critique, but I'll try to offer some advice anyway.
The biggest issues with this picture, I think, in order, are:
1. The background. Backgrounds are something a lot of people skip because they're hard, but this one really looks like it's been pulled straight from the first grade. The pony is actually much much better than the background.
2. Line thickness. It's not really consistent and tends to be a bit jagged, which makes the picture look messy. I'm not sure exactly what medium you're using to draw all this, but that's probably one of the first things I'd work on. (I'd actually just skip the backgrounds for now.)