Hi Ambi,
Perhaps for starters you start with a bit more simplified setup. Once you build up experience you can then try to play around with that build-in LPG of the Plaits. How about the following?
Connect your CV A (gate) from the A4 to indeed the gate input of an (ADSR) envelope, the output of that envelope to a VCA (CV input). If you have one more EG you could output that to a filter too; but you can leave out the filter part first. If your EG has a switch for the speed of the EG, for example: slow, medium or fast, then make sure that your EG speed roughly matches with your gate speed you "export" from the A4 towards that EG. So if the A4 provides a speedy gate, set the EG to fast and for example if the A4 provides a slow changing gate then set the EG to slow.
Then connect your CV B (1 V/octave) into the 1 V/oct of Plaits indeed, the output of Plaits (optionally through a filter) to the VCA input. Then output the VCA (optionally through a mixer) to your audio output module to send it from your Eurorack to your external mixer. Some members here skip that audio output module but my advice is to use an audio output module to make sure everything goes smooth; but technically it's possible without an audio output module if you are careful enough.
Start simple and try to get some sound out of it first, then continue to improve the setup :-) You also can show us here your rack layout then it's easier to advise you.
Good luck with it, and soon I hope you will have fun with it as well once you got it working and kind regards, Garfield Modular.
For review reports of Eurorack modules, please refer to https://garfieldmodular.net/ for PDF formatted downloads