Rhonda welcome to the group. Many things to touch on before I try and help.
You need to add your coachs information to the signature line, this will help folks get a better idea of your rig. Many folks here will be of great help but you will find that the more information you provide the better help you will get.
Why do you think you need a new water pump? Does it run but not pump, does it not run?
As for the drain of fresh water tank. Look under your unit for a hose coming through the floor. This should be close to were the water tank is located. There may be a cap or value at the end of the hose. Or depending on where the tank is located there maybe a value near the tank its self.
This winnebago page may give you some help. I looked at the plumbing page but there are different models of you brave year.
https://www.winnebago.com/owners/own...s-and-diagrams
Good Luck/ remember here more is way better