As a stereo pair or as two identical channels?

The pair option is in the settings, you add one to the other there.

Identical channels you just use the Group menus to link the two together.

Stereo pair them, or group them? 

I don’t know the difference between them being two identical channels, pairing them or grouping them as the set up instructions does not say anything about that. However, I do now know that I could have set each of them in different rooms and allegedly pair them. I did not do that so both speakers are set up as part of my ‘Living Room’. What steps can I take from here to get them to work at the same time and together?

Stereo pair speakers in the same room:

https://support.sonos.com/en-us/article/create-a-stereo-pair

Group speakers in different rooms:

https://support.sonos.com/en-us/article/group-and-ungroup-rooms

Do you want them to operate as a left/right pair?