Welcome to irv2 alan tek.
There are
many transfer switch's here are some with diagrams " USER MANUALS" of their internal wiring.
You should already have your shore 50amp line and you can trace the Gen wiring back to it.
My load center has two number 10 wires that you may see in your house they are plastic covered cables. You can verify the cables by taking off the load center cover and they should be connected at top of load center feeding into the 50 or 30 amp circuit breakers.
Install a surge protector to save your appliances control boards you will wish you had if you do not.