I don't have a clue as to where it might be in your coach, but generally these pumps are close to the fresh water tank. In my former Class C, that meant under the kitchen drawers, behind the electrical circuit breaker/converter panel.
Generally, there's no harm in unscrewing access panels and looking behind them, so I'd turn it on and keep doing that until I found the tank and pump. Don't be afraid to pull out lower drawers inside the coach, either. Just be sure to remove them so you can put them back in (i.e., no excessive force).
When you find the pump, install a winterizing kit, if it doesn't already have one. Ditto for a bypass kit on the hot water heater.
2008 Holiday Rambler Admiral 30PDD (Ford F-53 chassis)
2009 Honda Fit Sport