Hi Poetri, sure! And what a cool first name to have 
Your sketches are not bad at all, very good work! You are clearly a natural sketcher and have learned to confidently define your strokes. Sometimes they overshoot a bit too much for my taste, but that’s also a matter of style. My advice would be:
- Explore more in terms of drawing style. Try out more contrast in color and value, different line weights, work with drop shadows and backgrounds. Work towards an own unique style.
- Work on your ability to express textures and materials. Your stitches draw too much attention, maybe try a thinner line or lighter color for those.
- Make the step to 3d perspective.
- About design: think critically about what you want to explore with your sketches. It can be more fun if you give yourself a clear purpose for each sketch, so you develop not only your sketching skills but also your design thinking. Some of your later sketches are developing an own design style, almost a blend of puma, nike and adidas. See if you can create your own brand for a specific user group!
Looking forward to seeing more of your work.
-Ralph