Well. It's something.
One of the first things that pop out to me is the line work. It seems so unenrgetic. You need to work on the line weight and dynamic. It seems like you are using a technical pen. If you are, don't allow yourself to be limited by the tool you are using, make that tool bend to your will and desires.
As for the coloring, it seems you are trying to accomplish a lot. and I can see how that can be confusing in a world where we have all the colors we could ever want. Try limiting your pallet to 3 shades. Your base colors, your shadow colors and your highlights. Work with those and practice some color theory. You'll find yourself with a stronger understanding of how color works.
Work on your form a bit and try to get the feel of a 3D object down a little more. ON your sketch, don't be afraid to draw yourself some guidelines if needed. they can always be worked out for the final project.
As I said it is a start. Work on some sketching exercises and some normal art basics. Keep coming back to the art form and asking questions and I have no doubt you will see some good improvement.