Dude, good to see another pixel pusher! Great work so far, I like how you show interest in pixel art and then you go and actively try and learn how to do it.

Since you are new these three bits of information are going to be the most important for improving quickly.

1.) This is the most given advice and most ignored advice, practice. If you are up to the challenge pixel at least on thing a day. Do this over and over and I promise you will begin to see improvement.
2.) Draw and learn the basics of art, I began as a pixel artist. At first I wanted to have nothing to do with actual drawing and my work sucked because of it. If you understand the basic principals of art (perspective, form, lighting, etc) your art will stand above the others. For examples of this look at Elk, Aeko, Coco, Fae, and Dusty. They all know how to draw and their work shines because of it.
3.) Imitate, but don't copy. Imitation is super super important when learning any type of art. Don't straight up copy other peoples work but zoom in real close and study it. What makes it good? What gives it this effect? Why does this work? Try and understand why something looks the way it does and then try to find a way to put it into your own pixel art. Observe other people's styles and try to mimic them, don't worry about your own style because that will develop over time.

I hope this helps, this is information I would give myself when I started. If you follow this you will see improvement a lot faster than you may expect. You have an amazing community of students and teachers at your disposal, we are here to help you succeed. And finally, the reason you don't see more great pixel artists is because many of them get frustrated or busy and quit along the way. Understand this and know what this means, what type of artist will you be?