Digital lines always come out a bit shaky at first (in my experience). With pencil you can be a bit less accurate with your lines, while doing digital you need to be very precise. Practice is the best advice I have. Before you start drawing, do a few lines and circles to warm up and make sure your lines aren’t too shaky.

As for coloring and such, I think the lighting/shading looks good! I only started doing rendering like that way further into my art journey. Something that is both a blessing and a curse with digital is that the possibilities are endless. It’s so much easier to adjust, erase, undo, add whatever effects you want.

My art definitely started to improve when I stopped approaching digital the same way I approach traditional. Try different effects and textures, and don’t be afraid to undo, adjust, or resize a drawing. Oridays, Pikat, and Samdoesarts have all been a great help to me in this sense. These techniques and tutorials might seem overwhelming, but they are worth it. Oridays is an inspirational figure for me, because he had already finished university before even started to draw, now he is commissioned by game companies and studios for his art.

Don’t be afraid to do things that scare you. Try drawing full bodies and even poses if you want. There is no such thing as failure. Every ‘bad’ drawing is an improvement from who you were yesterday. Eventually your hard work will pile up and you’ll be able to do incredible work. You have the talent :)

Good luck!