As a recovering PC user, I can’t live without a right click, which of course Macs don’t have. Or do they?
Actually you can right click on a Mac: just press the control key (ctrl) and click, and you’ll be able to access those handy right-click menus in Zotero and other programs and applications.
Read Free or Die 
Or, if you have a mouse attached that is a regular PC -type mouse, you can get the same right-click results as usual.