To view a menu, position your cursor on the Menu bar, and click on it with the left mouse button. This presents lists of commands that you can execute by clicking on them individually.
Terminating a Command
You may terminate a command, or at least one level of a multi-step command, by pressing the Esc key on your keyboard. You may also right-click and choose Cancel from the right-click shortcut menu. If you would like to terminate a command using the right mouse button, you can disable the right click shortcut menu. See the Options|Configure command.
Selecting another command from the Menu bar will also terminate any active command. Hotkeys, however, will not terminate an active command.