GoKawiilIf you're setting up your Sonos speaker for the very first time, you're going to need the Sonos app for your smartphone or tablet. Said software is available on both the App Store and Google Play. Once that's downloaded, create a Sonos account and make sure your speaker and the app are connected to the same network. From here, the process of setting up your smart speaker shouldn't be too daunting.
Whether you're hooking up an old-school Sonos One speaker or are lucky enough to own a high-end Sonos Era 300, the setup process is broadly the same. After you've hooked up your speaker, open the app and select Start a new Sonos system, press Add your speaker, and the app should quickly find your Sonos hardware before guiding you through connecting it to your Wi-Fi network (so have your router's password to hand). You can then assign your speaker to a new room (at the time of writing, Sonos has 22 different preset names, ranging from "bathroom" all the way through to "TV room" — though you can also set a custom moniker).
After you've set up your first Sonos speaker, additional ones are even easier to get going. Just hop over to Settings > Add Speaker or Component to easily pair multiple speakers. It's worth noting, though, that if you're looking to put together a full-blown Sonos surround sound system, your surround speakers will likely have to be the same model (so a pair of Sonos Era 100s rather than mixing an Era 100 with an Era 300, for example). Additionally, you can pair your speaker(s) with services like Amazon Alexa by scrolling down to Add a Voice Assistant from the settings menu.