Pipe hammering?

If your pump is not properly secured, and/or the lines to it are against something, that might be a source of your noise. RV water pumps can be very noisy sometimes.

An accumulator tank should solve your problem.

Mine does this too. Not sure if it is air or not but we always use the tank and pump. I have tried getting air out of everything several times. Never had any luck. I had the wife keep flushing the toilet while I looked for the pipe that was doing it and wrapped foam pip insulation around the area. It helped but didnt take it all out. At least it doesnt wake everyone up in the middle of the night anymore.

There are many types of arresters. See homedepot.com or any hardware site to determine which is best for you. Your problem will be trying to locate a suitable space to install such a device. Theoretically, it should be near the offending toilet but good luck with that. You may have to first locate it just downstream from the main water line to see if will work.

Use a regulator or install a water hammer aresster.

Get a water regulator

Open the fixtures one at a time until you get good flow. Might have to hold the toilet foot pedal down until it flows consistant.

Sounds like air hammer, caused by air trapped in a pipe somewhere. Either way, best to get it fixed quickly. As air is compressable, an Air bubble can cause increased pressure in your water lines, and do massive damage. We encounteed air hammer at a campground recently, and it was hard enough to burst a backflow valve near the water heater. Turned out not to be as expensive as we were afraid of, but still, a burst water line can be very expensive.

If its air in the pipes,how does one go about getting it out? Sorry if its a dumb question

Water hammer is most often caused by air in the system. Second most cause, high water pressure.