You have a lot of model space that has no faces. I expect what you are seeing is SketchUp zooming to where you have the cursor. If it’s on empty space it’s easy to zoom past the model, especially when you are working with the camera set to Parallel Projection. Keep the cursor on some face or edge when zooming and work in Perspective. That will make things easier for you. Save Parallel Projection for your output.
Is this a project for school?