Your story should be divided into three “acts.” The first act is the set-up or establishing act. This is where you get to know the characters, the setting, and a hint of the conflict that will happen later. This should not take too much time for a short film. A common error is to spend most of your time on set-up (getting up in the morning, getting dressed, making breakfast, walking to the car…) Your job as a storyteller is to leave out this extraneous stuff and get into the meat of the story ASAP.
Also, something needs to happen to launch the story into the next phase. This is called an inciting incident. The inciting incident should hint at the larger disaster to come or conflict to come.
This is where your protagonist comes across obstacles, conflicts, or interactions that keep them from accomplishing their goals. Act 2 ends with a final confrontation. This does not always have to be an epic battle. Even better is a personal confrontation or a verbal disagreement with someone.
Climax: Act three begins with the climax. This is where your main character accomplishes their goals, the battle is won, or the main point is made.
Resolution: the story ends with questions answered, loose ends tied up, who lives, who dies, and of course everyone lives happily ever after.