First thing, your modular have Audio, CV, Gate/Tigger/Clock signals, but all is electricity and you can send everything in everythings (example an audio source in a CVIN) , but at the beginning test some “classic use” voice synth like VCO VCF VCA
the ENV gen is more use to modulate the CV IN of the VCF or VCA
a VCO OUT in a VCF IN then in a VCA IN
- an ENvelope Generator to open the VCA (in VCA CVIN)
or open the VCF (in CV IN) or both with a multiple before
and after you can test the VCF after or before the VCA
btw i think it’s better to put the fx (delay, reverb …) at the end of the chain, but all is possible 
, like whawha after or before distortion each is own taste
yes you can think like guitar with the modular too, the audio signal (guitare or VCO) and go to modification (distortion, filtre, …) but in + you can also with other source change the parameters of each modules by the CV input.
try a simple synth voice and try to modulate it with some CV
there’s also this thread with some simple patch example