Story Structure

You don't need to know everything that's going to happen in your story, but try to figure out as much as you can. It will change, and that's okay. Above you can see where I overlayed my main character's arc over a plot line. Notice how it has no specific events or details, just an idea of where this character starts and how they grow over the course of the novel. This might change, too.

There are tons of great articles on story structure out there. Here are a few I find most useful.
https://nationalcentreforwriting.org.uk/writing-hub/how-to-structure-a-novel/
https://blog.reedsy.com/guide/story-structure/
https://www.thenovelry.com/blog/a-guide-to-story-structure