The best advice I ever had when I was young and stating out beating was "keep you mouth shut and your ears open".
It's far more relaxed these days but it is still good advice. The gamekeeper relies on the beaters to do as he says quietly and efficiently and at the end of the day it his job that hangs on getting the birds over the guns.
That doesn't mean you don't have a good time though

The camerarderie and humour has to be experienced and you will love it
One thing though. When the gamekeeper shouts at the top of his voice
"whose bl***y dog is that too far out" do not own up if it is yours. Just try to merge into the background if it is yours.
You'll have a great time. Enjoy it.
Steve