Nope, once you have the hose connected make sure your water is set to "City Fixtures" vs. "Normal" (that's what it labeled as on our coach) and you're good to go. Use the water pump when using your freshwater tank.
Some campgrounds have very low water pressure - 25 psi. If you find the pressure this low, water will just dribble out of the shower. Turning on the electric water pump will raise the pressure to 45-55 psi. After you finished showing, just turn the pump off.
Jim & Roy Davis
2016 Hurricane 31S
1961 Rampside in tow
x2 on what Beau said. You don't say which coach you have and that makes a difference. On most coaches if you turn on the pump it's pulling from the onboard fresh water tank, it won't act as a booster to the city water. What happens is the pump is adding to what is coming in from your hose. For this to work you'll have to have water in your onboard tank. We always keep at least half a tank of water for times just like that, plus to use on the road.
Always make sure you have a pressure regulator at the campground spigot to be safe, some water systems have low pressure at certain times of the day and high at others.
Hope this is helpful to you.