Hi! It's so cool that you share your work, I really like the anatomy of the person, I see that you really captured the moment. On the other hand, the places where I see maybe you need more work is in the perspective, value contrasts, sources of light, and rendering shadows with pencil, maybe what you need is to try different hardness of pencils (4H vs HB vs 6B vs 8B) to see how they can help you to improve the values. I hope this is helpful, as a student myself I can tell you that drawing is something that you need to practice and also learn about theory because they really go hand by hand. Best!