I just moved into a house with built-in home speakers in several rooms. The previous owners said the speakers were set up so that there are different zones so you could play them all together or independently. They previously used sonos + pioneer, but I have no idea what this means.
I think i need to buy an AVR? How do I use the AVR - does it need to plug into anything - I see no wires for the speakers, but have no idea where to start if they're wireless? Where do I even start? How can I unlock the capability of playing around with different zones?
To power the speakers you first need to find out where they are wired to, if they are wireless you will need to look up their models and read about how to use them. Zones are setup by the amplifier you get to power the speakers. There is no secret way to sort this out without actually looking at the speakers and tracing the wiring from them or looking at the model if they are wireless. If you still have a way to contact the old owners can just ask them also. Sonos and Pioneer are pretty major companies for audio and video https://www.sonos.com/en-us/homehttps://www.pioneerhomeusa.com/
There should be a central place where the amp or receiver used to be for the old owners, that is where the wiring would terminate to power the speakers.