Well I did read a couple and I have to admit that I'm quite surprised. Are you sure you're 13? You writing style seems extremely advanced for a thirteen year old. Like... extremely good! I like your descriptions and I only noticed two mistakes in the second chapter of Summer Snow, but they seem like the type of mistake you do when you don't proofread. So that's my only suggestion for now.
Btw, I'm definitely keeping an eye out for your stories!