This youtube clip is a segment of a “This Old House” episode where they demonstrate the installation of an interesting kit for using portable generators with house electrical systems

https://www.youtube.com/watch?v=d9V4RjzUXV8

Also check out this device that goes between your electric company meter and house wiring to connect a generator available at Home Depot

https://www.homedepot.com/p/GenerLink-30-Amp-Meter-Mounted-Transfer-Switch-MA23-N/301961623

For sound reduction,
check out “Sonex” waffle surfaced foam,

https://sonex-online.com/

and the pre-fabricated sound reduction fences
made for Outdoor air conditioning units