There isn't really anything you have to do, but maybe check that the stove wasn't accidentally turned on. Nothing else on the trailer is an open propane connection.
Typically what I do is only open one tank. Then once that tank is empty, I will open the other one. This is kind of a warning system for me. Basically once one tank is empty, I know I have to run and fill it up. Whereas if you leave both tanks open, you won't know if you're out of propane until it's too late.
The only thing that I do once my trailer is setup as far as propane is concerned is open one tank and light the stove tops for a minute. What this does is get rid of most of the air in the lines between the tank and stove sometimes caused by traveling and changing tanks.
The fridge lights automatically. The range does not, you need a BBQ lighter to start it. The water heater does light automatically once you turn it on (there should be a red switch that lights up, close to your tank full/empty gauges).
What do you need to know as far as potable water? How the system works?
There is two systems in one on most RV's.
You can use "city" water connection which means that water from the onboard fresh water tank is not being used along with the pump not being used, but you must have a water hookup at your campsite. If you are staying at a site with water hookup you can get away with not having to fill your fresh water tank before leaving your house. The only downside to this is that there is no garuntee the water quality at the campground is up to your standards.
The other method is filling the fresh water tank before you leave on the trip. Then you will be using the pump any time you want to turn on the water. But you will have better quality water (as long as you filled it with good quality water at home).
IMO, I would recommend not using potable water for drinking or cooking. I have got into the habit of bringing water bottles along and that is all I use for drinking and cooking.
I hope that helps. Maybe someone can chime in if I missed something.
20XX 3/4 something TBD
2010 K-Z Spree 318BHS LX