Woops what did you press? All of a sudden your mac is telling you everything that is happening on your screen, and what’s worse you are in a public space and don’t know how to turn it off!
Don’t worry is really straight forward to toggle:
1. You can just hit cmd + F5 to turn off and on or
2. Browse to System Preferences > Accessibility > VoiceOver to toggle on and off.
Hope this helped!