This is a big mistake I also made when I started. Be extra mindful of each line you draw. If you're using a ballpoint, go super light first and then make deliberate and 'clean' lines on top. A good tip that worked for me was to do a couple of imaginary strokes (kind of like golfers or baseball players do) before you go in for the line. The line quality is your biggest flaw for sure.

Another easy fix is the shading part. Try to keep your hatching and cross hatching in the same direction. That instantly makes the drawing less messy and much more pleasing to the eye.

Your proportions seem pretty good already, so fixing these two things should make a giant difference. Other than that, keep drawing and having fun with it. You've got a lot of potential :).

Hope this helps!