how to connect sonos era 100 to a turntabe without wireless

You have asked two questions:

1. How to connect a turntable to Era 100’s

2. How to connect a Hi-Fi system to Era 100’s

Assuming you mean a turntable is it standalone or connected to a AV receiver via a phono input. The solutions are different.

It is a Sony wireless turntable 

I have spent hours trying to connect to Sonos with no joy

What model Sony turntable?

LX 310 BT

Here is a link. 

There’s two ways of connecting that turntable to a Era 300, Bluetooth or analog in.  

Bluetooth:

Start the pairing process on the Era 300:

https://support.sonos.com/en-us/article/pair-sonos-era-300-with-bluetooth

Then connect the turntable (Page 13):

https://pdf.crutchfieldonline.com/ImageBank/v20190527140900/Manuals/158/158LX310BT.PDF

Line-In (you will need the adapter for the Era 300, sold separately)

https://support.sonos.com/en-us/article/listen-to-your-turntable-on-sonos

Make sure you switch the Output Select switch on the back of the turntable to ‘Line’.