I'm still trying to fully understand shading myself so don't beat yourself up because it doesn't look right. No one starts off good, they devolupe and become better over time.
When I draw, I try to pick out things I want to improve upon the next time and don't over kill trying to improve myself then and there.
I'd say other points of interest would be to work on the neck, as it looks a little too thick and maybe theh ind legs would be my suggestion, which look like a ball with another arm/hand attached.
If you keep at it though you will get better over time. Don't forget the internet is also full of tutorials on how you can improve yourself. Hell, I just looked up one for hands as I need work on those myself. Not to mention you can learn a lot just by looking at how other people draw their pieces as well.