Running 12 ga wire to lamp post with 3 one hundred watt fluorescent bulbs,one small refrigerator in camper and rectifier in camper,80 feet from breaker box on 20 amp breaker, Comments?

I don't really get what it is you are asking, or doing.

How do the camper and post light share the circuit?
Is there going to be a receptacle on the post for the camper?

I will say, all that should be fine on a 20A circuit. 80 feet is not all that far.
How big is the rectifier?

20 A circuit breaker in garage to lamp post (#12 ga @ 80 feet), HD 20 A std recpticle in middle of line'Camper rectifier is for charging batteries.and I want to keep the refrig.running

Just make sure the receptacle is GFI protected.

Will do ,thanks a mil
Ken-o