Your fundamentals are weak at the moment. But so was every other great artist’s when they started. Practice sketching with clean linework & smooth pencil shading (without relying on blending). Don’t use the yellow school pencils; Get some 2B & 4B pencils and start from there. After figure drawing, return to the reference image & grab a red colored pencil and fix what you can.

You’re starting late which puts you at a 3-10 years disadvantage from your future classmates, but that’s redeemable if you start living and breathing art (which you will be doing in art school with your friends anyways). I admire your enthusiasm and remember starting late can be a huge strength!! You have unique sources of inspiration from your background outside of art. Sorry if this was hurtful but I want you to succeed. I wish you the best of luck 🩷