Pan and orbit not working with middle mouse button and alt+mmb?

To this first create a rectangle with the RECTANGLE command. Then use the CYLINDER command to create a cylinder. Finally use the ALIGN command to model the square shape in the cylinder.

To bring back the arrows on your object, go to Customize the user interface. Then search for Transformation-Gizmo show then choose and assign a button. Afterwards close, press this button and you will see the red lines. Lastly, go to Settings > Gizmo and enable Gizmo again. Then click done.

To remove unused maps on your computer go and sign into My Maps. Adjacent to the map that is to be removed, click on the three dots and select Move to trash. The map you removed will stay in the trash unless you empty out Google Drive.

To make object more transparent go to the visibility option in Object Properties. In this panel lower the visibility after selecting the object.

To close the perimeter between two surfaces, use the Bridge tool or connect the vertices/edges manually by selecting them and using the Connect function. This will create a connection or edge between the two surfaces, closing the perimeter.