The three things every story needs
'Once, a lonely dragon in a cold cave wanted a friend' — that one line already has a character, a setting, and a problem. Every story, from a bedtime tale to a blockbuster, is built from those three pieces.
Who, where, and what goes wrong
Every story has a few building blocks. The characters are who the story is about. The setting is where and when it happens. The problem is what the characters must face or fix — without a problem, not much of a story happens.
The problem drives the story
A lost puppy, a locked door, a big race — the problem is the engine. The middle of the story is the characters trying to solve it.