I had many ideas when I was 12. However, all of my ideas were written about by men who have lived and died decades and centuries before me. I had this problem as a child and teenager where I would sit alone (mind you this is before I had internet) and think of as many concepts as humanly possible. When I got internet, I quickly learned that even my most esoteric mental machinations were conjured up by obscure individuals long before I was born.

If you're going to write stories for commercial success, write to a specific demographic or target audience.

If you are writing just for the sake of it, make your story as readable and thought provoking as possible. You want potential readers to value your writing. Don't get wordy. Don't write horrifying material that no one will like.

Good luck