Ideas are not tied to page numbers, so don't let the complexity of a character or plotline fool you into thinking you are dealing with a novel idea and not a short story idea or a play idea, for that matter. James Joyce originally planned for Ulysses to be a short story in "The Dubliners." If you haven't written much and you want to try your hand at writing, my suggestion is to choose the form that interests you most. See where it takes you. The opposite approach, trying to fit an idea to a format, can be extremely frustrating.

Ideas are not tied to page numbers, so don't let the complexity of a character or plotline fool you into thinking you are dealing with a novel idea and not a short story idea or a play idea, for that matter. James Joyce originally planned for Ulysses to be a short story in "The Dubliners." 

If you haven't written much and you want to try your hand at writing, my suggestion is to choose the form that interests you most. See where it takes you. The opposite approach, trying to fit an idea to a format, can be extremely frustrating.