Nice start! First of all, don't stop making pixel art! Stephen King once said:
“If you want to be a writer, you must do two things above all others: read a lot and write a lot. There's no way around these two things that I'm aware of, no shortcut.”
Here some suggestions on how to improve:
1. Proportions - Try to figure out the right ratio between legs, body, arms and head
2. Work with Color palettes - in most cases, blue isn't simply blue - it can be a mixture of a lot of more colors. Also, I noticed your palette in this picture is quite dark - which might cause a problem in some cases
3. Details - I know it's hard to add necessary detail in pixel art, but it is possible to find the right balance
4. Copy, Rip Off, Steal where you can. Nothing is sacred! (As long as you learn in the process and respect other people's art)
5. Nobody is special - don't expect too much!
Hope that helps! Feel free to send more pixel art!