You’ve outlined your setting including research into what it was like way back when. If lucky, you visited the cities and are familiar with buildings, streets and plants. Your plot takes the character all over that environment, in and out of predicaments determined by geographical elements.
Have you taken into consideration how time changes the setting? Does it snow in winter, pour in the spring and roast in the summer? Is there only one season because the story is set on a planet, far, far away? If the setting changes/doesn’t change, how does this affect story?
A time traveler might have to find clothes if they’re dropped into a winter landscape. Perhaps the desert figures significantly in the story as your character rides a camel over dunes. However, what if the story never changes location: it’s always in the same city, the same house, the same neighborhood? Change still has to take place.
Your task is to write a story in which significant changes in setting occur that affect plot. Begin by listing those elements that would most likely happen based upon where you’ve chosen to set the scene. For example, during the length of the story will seasons change? Will a catastrophic weather event destroy homes, streets, lives?
Once you’ve chosen the changes that can logically be incorporated into your story, begin writing. Remember to include details so that readers can “see” the changes both in nature and in terms of how the changes affect your character’s thoughts and actions.
Have fun with this one.