Short screenplay provides examples of some of the tightest writing! As an exercise, take a few moments to watch just the opening of this Twilight Zone episode, “Mr. Denton on Doomsday” (written by Rod Serling).
The scene begins with close focus on a man, and then the world expands, one detail at a time. A bottle, a carriage, a pistol. The face of a man silently watching.
Ask yourself, where should your story begin?