Structure is but a small thing. A little bit of concentration and you can sort that shit out in about twenty minutes. Make sure you hit the plot points and the pinch points and you’ve “nailed” structure.
Structure is knowing that a sound basement goes on the bottom, a waterproof roof sits on top and there should be at least two doors. For safety. (Windows are optional, but a house without windows is stupid.)
But a structure is meaningless if you don’t have a story. And characters your readers want to like. And hate. And a premise that is something engaging and, if at all possible, unique. Use the structure to map out a trip. A story trip. Use Act One to really define your character’s world. Set up the hero to be likeable. No, make them loveable. And then put them in a situation like they’ve never seen before.
Someone suggested a good start for a story – a trigger for the story – would be: “What if you showed up at the train station to go to work and you were the only person there.”
Now, that’s an interesting scenario, but it sucks as a story. (Sorry, John.)
Is the person arriving at the station the hero? What was their life like before that? Is the story the lack of people, or is the lack of people the status quo (automatic trains) and the “story” is the appearance of a second person one morning? And how they fall in love? Or maybe the second person is an assassin. Maybe there’s been an evacuation order and the hero missed it, and as the only person inside the quarantine zone he manages to save the world.
There are, literally, millions of stories that can be wrapped around an empty train platform. Spend most of your time working out which of those stories you want to tell. Only spend a little on the structure.