How do I structure a story?

[Cel]

I have this cool plot but I don't know how to expand it into a story

Whenever I get a story idea, I create a google doc to go into detail with plot summary (start with simple, then a more detailed one later), characters (looks, personality, strengths/weaknesses, etc.), and chapter planning. For chapter planning, I basically put something like "B1, C1 - <basic desc>", in which 'B' is book and 'C' is chapter, and the description would be like an individual summary of the chapter itself (kinda similar to the plot summary). Eventually when I feel ready to start writing, I'd begin draft one on a new google doc and write it out, then eventually get to draft two or final version where you rewrite certain parts that may have seemed rocky to the beta readers