take over system from prior homeowner

Factory reset each device: https://support.sonos.com/en-us/article/reset-your-sonos-product

Then download and run the Sonos app.  Choose “Set up a new system” from the opening menu.

First, make sure which app the Amp you have is compatible with:

https://support.sonos.com/en-us/article/sonos-app-version-compatibility

Some Sonos devices like older Connect Amps, Connects and Zone players are only compatible with the S1 app, while the Playbase can be controlled by either app:

Then you can factory reset all the Sonos products, download the compatible app and create an account. You should then be able to add the Sonos products to the app.