Playing audio from Mac computer

Easiest is to follow this:

https://support.sonos.com/en-us/article/add-your-music-library-to-sonos

Alternately, if your Sonos speakers support AirPlay 2, you could use your normal player on the Mac, and connect to your Sonos speakers using that system. 

Ah, forgot…the PLAY:1s don’t support AirPlay 2, so you can ignore that part of my reply.