CommanderD, you're very young! From what you've posted here, it's apparent that you don't have a grasp of foundation skills. These foundation skills are extremely important if you wish to create any kind of art at all. For example, you say you like cartoons. But a cartoon style is merely a simplification of real life. You need to understand basic lighting, anatomy, form, mark making, etc, if you want to be any good at art.
Pixel art is just as much a medium as acrylics, markers, crayons, digital paints, or pencils are. The master painters would have been good at pixel art merely because they were good at art.
But pixel art is a somewhat slow and sometimes tedious medium. I would suggest working on your general art and drawing skills with pencil and paper, pen and paper, just something analog. Drawing on paper is much quicker and you're sure to learn much more from it. Because of your age, you haven't had as much time as the rest of the people on this forum have had to hone their art fundamentals, but it's a necessary step to get your art looking better.
I would recommend visiting
www.conceptart.org and starting a sketchbook. It's a wonderful place for young artists because you'll be surrounded by professionals. I've seen young people start sketchbooks with very poor drawing skills progress to professional levels in a matter of years.