If you have a mouse with less than three buttons or a keyboard without a numpad,
see the Keyboard and Mouse
page of the manual to learn how to use them with Blender.
The Orbit gizmo at the top can be used to rotate around the 3D Viewport.
Hovering over the gizmo and dragging with LMB will orbit the view.
Clicking any of the axis labels will Align to that view.
Clicking the same axis again switches to the opposite side of that same axis.