For zooming use the mouse scroll wheel.

For panning keep the middle mouse button (scroll wheel) pressed whilst moving the mouse. Panning changes the Viewpoint and Target at the same time

For rotating keep the middle mouse button (scroll wheel) and the [Alt] key pressed whilst moving the mouse. Rotating the view changes the Viewpoint only.

Per default, the Camera Interaction Mode is set to "Zoom". As soon as you change the view, e.g. rotate it, the Zoom button is highlighted in orange. The R-button applies the default view and resets your changes. The same happens when you use the shortcut [Ctrl + 0] or choose the command "Reset Camera" from the right-click menu.

The other Interaction Mode, "Parameters", is of interest when you are in a Camera or Output view. Any view navigation is now represented in active Viewpoint and Target parameters, hence can be stored to the timeline. In this mode, only the R-button resets parameter changes.