It’s day 4 and the writing’s good. If my Nano writer buddies are any indication, everyone’s still slightly ahead of the curve. So today’s a good day to shore up some structure. No, don’t go rolling your eyes at me. You don’t want to get to day 30 and realize that your story has no backbone, do you? Then listen up.
At this stage in the piece, you’re still in PART ONE, in which the main character’s life was going along just fine, until the event occurred that changed everything, or the person arrived that changed everything. That’s THE CATALYST. So you’ve been writing about THE CATALYST and how your character is dealing with said CATALYST. Now here’s the Very Important Plot/Structure part: your character has to do something (ACTION) that a) moves the story forward, and b) reveals something about their personality and their personal GOALS. Your character’s goals will probably change as the story goes along, but for now, you’re dealing with the current goal.
Is the GOAL to avoid conflict? Confront it? Beat it down with a stick? That all comes back to their personality. And your character’s personality will drive their action. And their action will move the plot forward and take you to PART TWO, where the main character actively participates in trying to circumvent/solve/defeat/rectify whatever the CATALYST brought.
So, to sum up you have:
THE CATALYST (the thing that happens or the person that comes along)
THE GOAL (what your main character wants)
THE ACTION (the thing your main character does in response to the catalyst, that also aligns with her current goals)