Simulate a right mouse click
You can make it so that, instead of clicking the right mouse button, you can just hold-down the left mouse button for a while to do the same thing. This is useful if you find it difficult to move your fingers individually on one hand, or if you have a specialized mouse.
Click the icon at the very right of the top bar and select System Settings.
Click Universal Access.
Select the Pointing and Clicking tab.
Switch Simulated Secondary Click on.
You can change how long you must hold down the left mouse button for before it is registered as a right click. In the Pointing and Clicking tab, change the acceptance delay under Simulated Secondary Click.