Because Audacity is a cross-platform application, and traditionally Mac computers have not had a right mouse button, “right click” is currently not used much in Audacity. In the current 2.1.1 version of Audacity, there is a right click menu on the Timeline (the time ruler above the track area).
The current version of Audacity is available here: http://web.audacityteam.org/download/windows
Please also see: https://forum.audacityteam.org/t/important-information-for-windows-xp-users/37650/1