It’s honestly not to hard, other than wording (for me, at least). Just find an idea you like, spend some time thinking and planning if you want, or just hop right in and start writing it out. The first couple things you do might not be great, but the more you practice, the easier it becomes and the better you get at it. I’d recommend keeping anything you start out with, though, so you can come back to it later when your skills have improved and rewrite it, if you still like the idea. Let me know if this helps!