RV Repair: Hot water, pilot flame, hot tank

Question
First time we've used the rv, struggling to get the water heater to operate.

We had to replace the plug in the tank, then ran the water in order to fill the tank. It doesn't want to kick in after that. It has come on twice but both times shut off again

We have propane and the water tank is 3/4 full. I'm not sure that there is water in the hot tank for it to heat so that's why it shuts down

Answer
shut down may be due to restricted gas flow, from spiders or dirt in the lines/regulator.  It may be due to thermalcouple is bad.  That is the copper thing the pilot flame heats up when the burner is not going.  It may be a problem with ventilation for the burner assembly.  Another possibility is the thermostat setting or faulty.  I know that when you first start the pilot, the gas lines need some time to fill completely.  Possibly 10 minutes before you light the pilot.  Good luck.