On the transfer switch you have three sets of terminals, Depending on if it's a 30 or 50 amp switch will determine how many terminals in each set, Since the generator is only a 120 volt (single out) I will give you instructions for both.
First, locate the main power feed to the power distribution panel, Remove it, this goes to the SHORE POWER terminals on the switch
A new set of wires (Same guage or larger) goes from LOAD to the master distribution panel.
The cord from the generator goes to the GENERATOR terminals.
IF it's a 50 amp.. Then you jumper the two hots together on the Generator side.
Home is where I park it!