Some thoughts on narrator:
The narrator is the most powerful tool that the writer wields. Being so, it must be handled very carefully. Narrator determines how the reader views the world. It is called Point of View or Perspective.
There are three main categories of point of view: first person, third person, and second person. Subcategories for third person include third person limited and third person omniscient.
The choice of point of view depends on what knowledge you want the narrator to have, how reliable you want the narrator to be, and what level of engagement or intimacy you want the reader to feel.