Here are some quick tips for short stories.
1. Start with a character who’s got a problem
Your character has a problem – by the end of the story, the problem’s been solved. Your character’s goal, and the obstacles to achieving it, comprise the plot of your story.
The great writer and critic E.M. Forster gave this popular example of a story and a plot:
The king died and then the queen died (story).
The king died and then the queen died of grief (plot).
If your main character has no problem, you can end up writing a vignette. Generally speaking, these aren’t satisfying to your reader. You’re aiming for a short story, with a beginning, middle, and ending.