I would suggest you write down the main scenes of the story. It can be in paragraph form and should just be overviews of the action. For instance:
After that, decide how many pages you would like to spend on each scene. You can choose several pages for each scene or just a single page. For instance, the first scene with the bears could be one page, or you could stretch it out to multiple pages.
After that, show your descriptions to other people and see what they think of the story. How well does it flow from scene to scene? Does it have a good ending? Is it interesting?
After that, it would be best if you find an artist. You should have your artist included early in the project. That way they can lend their creative ideas to how the pages should look. You should include your ideas about the page layout, of course, but don’t write a complete script with every scene, page, panel, pose, and balloon already decided. That won’t allow your artist to make any decisions and they won’t be as invested in the project.
Sounds like some good ideas!