How to hook up the water to a 1988 prowler travel trailer?

Dont know the exact specs on your model, but most trailers have water tanks that you fill. They either have the hookups in the back, or along the sides. sometimes fairly obvious where they are--other times the hookups are inside some locked doors along the side.

BUT, i was going to point out that many trailers dont hook a hose up to get water working--they often have a place (under seats, benches, cubbords, etc) to put a car battery--that powers a water pump. without this, you will not have running water, even if you've filled the tank.

but, if it's not right on the outside of the trailer, saying "water here" then it's under a flap, or behind a door... usually on the 'drivers' side of the trailer. keep looking!

and enjoy the camping :-)