The Great Gatsby is presented from the first-hand point of view of Nick Carraway. The entire story is narrated as if Nick is remembering and retelling the adventures of his life living in the East, with the exception of the very beginning of the book when he sets the scene from which the memories arise and reflects upon the lessons of life he learned as a result of his time there.
The story actually starts with Nick explaining how he came to the decision to relocate to New York. From there, he goes on to describe the people he met, some of the experiences he shared with them, some of the observations he made of those persons and the lifestyles they followed, and his reactions to those insights. Through it all, the story is based upon Nick looking back at what had happened in the past.