Ok, the plug should be fine for now, but probably should have been an anode rod, (look it up at camping world). Now you asked about water pump, you didn't give model number, year, or anything. With over 200 floor plans and trailer styles, how can we help?
Now for water, are you connected to a water supply? (city water), Or is your fresh water tank full? If connected to city water, forget the pump, don't need it.
Since you have the water heater plugged, and when you think you have water, go back to the water heater and open the "pop off" valve, at the top of the heater, above the plug u
you put in. If you have water coming out, then we'll help you get it lit.
2012 Ford F250 ext. Cab 4x4
2002 Jeep Wrangler Sahara
2008 Yamaha V-Star 650 Classic
2008 Work and Play 18LT