There are no original stories left. Anyone that has read any French or Spanish novels from the Middle Ages can tell you that.
All stories boil down to prince, princess, evil vazir, save the world, for a given definition of prince, princess, evil vazi, and save the world.
The best that you can achieve is a unique voice, if you work at it.
I would suggest that you create an interesting character (not impossible for anyone) and proceed from there.