Make sure the range top controls, the furnace, and the water heater are turned off. Turn on the service valve at the LP tank and check for any leaks at the fittings you can see. If your range top does not have an igniter, with a match or BBQ lighter at hand and lit, turn on one range burner and hold the match/lighter close to the burner holes until the burner lights. It may spit and sputter a little bit as any air is cleared from the gas line. Once that burner is burning steadily, light the others and leave them on until they too are burning steadily. Next turn off all of the burners and turn the furnace on at the thermostat, setting the temperature as needed to make it call for heat. After a 20 second or so delay, you should hear the blower turn on, and 10-20 seconds later the burner will ignite. The burner may take a couple of tries before it lights, again to clear any air out. If the fan runs more than a few minutes without the burner lighting, the control bard may have gone into lock out due to no ignition. Turn the furnace off and wait a minute or two before trying again. Once the furnace lights, it will relight as needed. The water heater is next, after making sure it's full of water. Turn on the switch and listen for the burner to ignite. If tries three time without lighting, it may lockout. Just turn it off and wait a minute or two before trying again. Like the furnace, once the line has been cleared it will continue to relight as needed. The refrigerator would be the last item to check, and may also take the ongest to get any air out of the lines if it's been sitting for a long period. It may take quite few retries to get it to light the first time. I had one take almost 50 tries before it finally kicked in, and was fine after that. Take your time and don't rush the process.
