Try not to start with that level of detail. Get the skeleton of your story together first. That will not only help you make sure the elements of a satisfying story are there, but it also helps with pacing later. Here's a template. You don't have to fill in all the blanks yet.

1. Ordinary World. Describe the daily life of your characters in the beginning of the story.

2. Inciting Incident. What happens that triggers the conflict in this story?

3. Refusal. Describe any initial refusals on the part of your characters to face the conflict.

4. Describe the moment when your protagonist(s) makes the choice to face the conflict.

5. Describe the moment when your protagonist(s) crosses the point of no return and cannot change their mind.

6. How will your characters get from the point of no return to the climax?

7. Complications. List things that go wrong on the way to the climax.

8. Climax. What happens that changes everything and results in the ultimate resolution?

9. Resolution. How does it turn out in the end?

Cheers,
Michelle