How to use QuickTime Player from apple Support: https://support.apple.com/en-us/HT201066
Alternatively, Mac users can also download the apps SnagIt or Screencast-o-Matic with similar features.
SnagIt Home Page: https://www.techsmith.com/snagit.html
Screecast-o-Matic Home Page http://screencast-o-matic.com/home
VoiceThread is another free tool that is more of a presentation-style option. It is not a screen recording tool, but it is a tool that allows you to build and record a presentation within it, using slides you've created that you can navigate through.
VoiceThread Home Page: https://voicethread.com/https://voicethread.com/
Finally, there is a Chrome browser extension called Screencastify that can record anything within the browser, such as a Google Slides presentation or a Prezi.
Screencastify (you must be using the Chrome Browser to install and use this tool) https://www.screencastify.com/