hi there! my answer for you would be to really identify the story's plot, the way the story uses characterization, and the primary conflict in the story. and that's the best advise i could give you.
learned most of this from google so if youre still confused, you can go ahead over there!
hope this helped even just a little. have a good one!
edit:
also, here are a few story themes to give you the idea...
Good vs. evil.
Love.
Redemption.
Courage and perseverance.
Coming of age.
Revenge.