Simply reset the Sonos App when at your office and setup the new Sonos speaker - but are you sure you want this speaker setup on a different system? - personally I would leave it as part of the same Sonos Household, but it’s a matter for you. See my comments later.

When you return home, connect the mobile back to your home WiFi - reopen the Sonos App and connect it back to your ‘existing’ Sonos home system. 

The App will switch between your Home/Office Sonos systems as you switch the mobile device WiFi connection.

My only reason for suggesting you use the same Sonos Household/System for both Home and Office, is that some services like Amazon Alexa, or Google voice assistant, can only use one Sonos Household at a time - so, as an example, you would not be able to use the same Alexa account and services at both locations, but if you use/extend the same Sonos Household to cover both locations, the voice service will then work at both, plus you will not have to reset your App. You simply add the office WiFi credentials to your existing Home Sonos system instead and setup the device first on your Home system, before taking the speaker to work. In this regard, you may also find this link helpful…

https://support.sonos.com/en-us/article/connect-sonos-to-a-new-router-or-wi-fi-network

So, currently my husband and I each have the Sonos app on our phones which we use to control the home system. He works from home. If I set up the speaker as you recommended, leaving it as part of the same household, and then I take it to work, will he be able to use tue other speakers at home on the home wifi network while I am simultaneously using the new speaker at work on the work wifi?

Also, I’m certain much of my confusion o. This is tied to the fact that I don’t understand the difference between a system, a network, and a household. Can you please explain what it all means and how it all works with Sonos?

Amazon only allow one music stream across the various players (sadly) even if they’re in the same Home location, but the same service can be operated across multiple locations if you don’t stream at the same time - if you need to play multiple streams, then a family music account is the best option to choose.

Ok…not sure what Amazon has to do with anything related to this thread. We primarily use Spotify (although I’m not sure what that has to do with it either). Can you dumb this down a few notches for me please? My question is related to the setup within the sonos app/system/network/household/account/whatever.  

The end goal for me is to have all of my home sonos speakers connecting to my home wifi, my office speaker to connect to my wifi at work, and a single login on the sonos app to control each with ease of switching between the two. All I need are the simplest most dumbed down way to achieve that (pref with step by step instructions).