Select the "Navigate" radio button to enable the default panning interaction with the map - click and drag to move the map in one direction or another, and use the scroll wheel on your mouse to zoom in and out.
Tip: Think of Navigate as your "home base" - after sketching in new geometry with one of the drawing tools, it's usually easiest to reactivate "Navigate" mode, which has the effect of turning off any of the drawing or modification tools. This means that you don't accidentally add unwanted geometry the next time you click on the map.