Let’s talk story beats briefly.
They can be an elusive concept because they can scale large and small.
The best way to think of it is as a unit of action, in either a scene or story, that represents an event, plot point, or step that moves your character towards their outcome.
Therefore, a beat could describe the acts that get you to the end, the scenes or sequences across those acts, or the minor story beats that move you across the scene.
Story beats are helpful while planning out your story. Again, you can scale them to your needs. They can map your way through stories, acts, sequences, and scenes.
And to reiterate the point, the more you focus them around a story event—the progression forward or backward of your characters towards their story want—the more valuable it’ll become identifying them.