I'm sure that there are many things that you will want address about making this new vehicle a portable home. Therefore I suggest you find a online support group for RV owners. Like the good Sam club perhaps of other Coachman owners. They will be able to help you to have a enjoyable and pleasant travel experience.
You can try using storage tank to sanitize the freshwater system in the 2002 Coachmen Pathfinder. You should ensure that the tank capacity is full. A margin of safety should also be left while the sanitizing process is done.