There are three acts to a story - beginning, middle and end.

Consider a 100K word novel.

You spend 25 K for the beginning, 50 K for the middle and 25 K for the end.

Each scene or chapter should ideally be around 2K words. Why? Because readers can’t quit in the middle of a chapter. 2K words is a good enough length, a potato chip length, where the reader will keep reading one more chapter.

This comes out in terms of scenes - 12 for the beginning, 25 for the middle and 13 for the end - more or less.

There are fifteen scenes that each part needs to have -

1. Inciting
2. Complication
3. Crisis
4. Climax
5. Resolution

So that’s 15 scenes done. Now, for the rest of the 35.