You need to have some kind of a theme/motif. For example, the theme could be friendship. Or maybe loyalty? How about betrayal? Corruption? Forgiveness?
You also need to have a compelling conflict, such as man vs. nature, or man vs. man, or man vs. fate, or man vs. machine, or man vs. himself, and so on.
You need to have a dramatic structure–the setup for the premise/narrative, the introduction of the conflict, the resolution to the conflict, aftermath, and so on.
Your ending has to compelling too. An ideal ending often is unexpected, logical, yet inevitable.
You also need to have character development/arc. For example, is your character going to be changed by the events in the story? Does your character remain steadfast regardless of what happens? Is this story about growing and changing, or is it about tenacity/will?
Pacing is also important–how you arrange the quiet moments vs. the busy moments, the timing/beat of each scene/shot, and so on.
The use of irony is often a very good storytelling device–especially for the conclusion of the story.
These are just some basic storytelling techniques/guidelines to think about. If you googled “storytelling techniques,” you’ll find even more.
(BTW, we used to have a sub-forum for storytelling/screenwriting, but not enough people used it so we closed it.)