All good points Todd. Sue, does the stove top burners light. I've found that's usually the easiest place to purge from. Are you 100% certain the propane tanks contain propane?
The water heater and fridge are more difficult appliances to light when the lines have not been purged of air. The stovetop is the easiest.
Hope that helps.
2016 Ford F-350 Lariat CC, 4x4 SRW. B&W turnover with extender. 2015 CC Silverback 29RE, fitted with Reese Goose Box. Amateur Extra Class K5TS, 2016 nights camped 16