Yo. I'm a 16 year old too, so my advice is probably not too great but i want to be an editor so hopefully i may be able to help... I think the first thing you need to do is write down a few key words or phrases, descriptions or lines from your story, on a piece of paper, not on microsoft word or whatever, so you can make spider diagrams, add things/ cross things out. Then you need to think of a beginning, middle and ending. Start of vague, maybe just think about what you want to be the "moral" or point of the story to be. Just keep writing down anything you think of, any inspirational lines on existing stories, things you may want to include, little pictures of the main character's clothes (weapons? If you're doing that kind of story) but don't think about writing the story. Just write down ideas and mull over your fantasy any time you can, Like when i'm in bed, i create my own little stories before i go to sleep. Then, eventually when you think you're pieceS of paper are full of ideas and other random pictures, write a rough draft. Start very rough, then with a red pen, move paragraphs around, cross out things when you think it's getting boring, and then add more info, descriptions and story. I think of stories like bodies; first you have the skeleton, which is the plotline, which has to be strong and pretty flexible. Then the meat and muscles are the story telling. They strengthen the the body, make it move, get it going. The organs are the characters, they're essential, as bodies can't function without/ with bad ones; they need to be perfect. Then you have the skin, which is your audience, as skin shows age. Think about the audience you're targeting and use suitable language (ie don't use long words if it's for children) Then the clothes. Perfect your story, keep preening it, make it look nice, neat and tidy.