thumbless welcome to irv2.
What size are the wires you have coming out of Gen?
If they are heavy gage you should find some info on how to wire on the link provided.
The two black wires would be split between the two sides of your load center, the two whites would go to the common ground buss of the load center, the green would go to frame cover of load center housing. There maybe a connection for the green wire on back surface of load center. Green is a safty ground in case of poor grounding off white wires a applience ground you some times see on your appliences.
You should also have a heavy number 6 ground wire to frame of coach where you will see other heavy grounds from frame of Gen you will place, converter, transfer ckts etc,etc.
You may have two pairsof ckt brakers from Gen feeding your two pairs of white and black wires.
If you have no clue whats going on find a electrician or a friend who can help, and when your working on power EVERYTHING is disconnected.
While your at it you should add a surge protector to have complete job.