Let's make this easy:

first:  describe the setting.  Where is the story taking place?  What time of year?  When exactly? Is it in the 18th century?  Is it in the future.

next:  What is the tone of the story?  Is it funny, sad, fantasy?  How does it make the reader feel.

next:  Introduce the main character, the protagonist.  Describe him or her.  What is his/her problem?

now:  Who is the antagonist in the story, the person or people who are fighting against the protagonist.

Describe the conflict.Give examples of the rising action.  Show how the conflict intensifies.  Now explain what the turning point is of the story.  This is when all the action shifts and the conflict begins to be resolved.  How is it resolved?  Explain this.  Now you have a plot summary

If you are assigned to write a plot summary of a short story, you are being asked to analyze the main plot elements and then organize the results of your reading into plato categories. Avoid simply giving a page by page precis.

A plot is usually an action consisting of some conflict between a protagonist and either external circumstances or other characters. Thus to summarize a plot, you first need to determine the protagonist or main character of the story. Next, you need to determine the main conflict and how (or if) it is resolved. Finally, think about how the character or the environment is changed because of the resolution. Other elements you should include in your summary are setting (is the story set in a palace? a slum, wilderness?), timeline, other characters (especially antagonists if there are any), mood or tone (is it funny? tragic), and viewpoint.