The green light symbolizes ambition, desire, and longing. This is the longing to belong to a different class, a different life, a different identity. The book ends with an image of boats beating against the current, desperately striving to reach something (like the green light across the harbor) even as the current carries us back and back to where we came from.
thios is easy you just make up characters then you put the setting which your your story is abot then you make a problem put to things that made that problem in rising action put your climax make a solution and then make a theme that is all and it is easy because you make your own story i am in flvs to and i got a 90% on that so good luck.