Hey CarminoRusso,
I would say that you have to use the RCA output of the second zone with the amplifier. But it is questionable whether all this really works well. Basically, the whole thing is in stereo and analogue. But it will work with the Sonos Connect.
Greetings wOOOx
Most likely your record player has a cinch connection and then you can connect it without further ado. For cinch see https://de.wikipedia.org/wiki/Cinch