trying to set surround using old speakers and amp

You can't do surround (4.1 independent channels) but you can play all of them together to get a more room filling sound.

Set the Play 3s to be a stereo Pair, then Group them with the Connect amp.

For the Sub, try it Bonded to the Connect and the Play 3s and use it where it sounds best.

Note that as per your request in the topic title, as well as the text of your message, this will not be surround data. If you can figure out a way to get the stereo output from your TV into your Sonos system, the best you’ll get will be that stereo…and if you group a second ‘room’, it will be the exact same signal, in stereo, and not any surround data. 

Another thing to note is that any analog input (such as on the CONNECT:AMP) to Sonos must pay a 75ms delay, which Sonos uses to both change the analog input to a digital signal, and to prepare it for distribution to any potential other Sonos ‘rooms’. 

For me that delay, speaker audio from the TV's video, isn't enough to be a problem.

Where it is more of an issue is when it is between speakers and gives an echo effect. 

Still if not willing to invest in a newer Amp with a a TV input and surround circuitry it isn't a bad option. Easily removed too.