If you have a 3-button mouse, which would be best, use the scroll wheel by itself to zoom, press the scroll wheel to orbit, and press scroll wheel with Shift to pan. Don’t touch Ctrl while navigating around your model.
By the way, it would be a good idea to learn to make components and groups of the content youa re modeling.
If you ever do want to place the camera inside the room, while on Parallel Projection, a change we made about a year ago means you now need to use the Position Camera tool to place and drag in the direction you want to look in, then only use zoom and pan to change the view. If you orbit after placing the camera, its position will be moved to be outside of the building.