If you bought the fifth wheel from a dealer, you should get a walk-through to give you some idea of how things work. But even with that, they may assume you have some general knowledge of RV systems. So a couple books or videos are a good way get you started.
You can also use our site search to search for posts related to the issues you are encountering. As you will find, there are nuances among the different types, models and brands of RV, but you may find posts that will help you start to troubleshoot some of your specific issues.
If you just recently purchased the RV, whether it is under warranty or not, then your best option is to take it back to where you purchased it and have it repaired at their cost. If the seller will not help or you’ve had the RV for some time then you have two choices: diagnose and fix the problem yourself, or take it to a repair facility.
Try the following before you visit a repair facility:
Reset all of the RV’s breakers that supply power to the 110 Volt wiring.
Make sure your propane is on – the best place to test this is to see if your propane stove lights. (CAUTION: Do not use a lighted match/flame anywhere near propane).
Reset the LP and carbon monoxide detectors
Unfortunately you did not mention if the problem with the electrical was on the 12-volt or 110-volt side. Usually, your lighting is 12 volt and your electric outlets are 110 Volts.
You also did not mention the source of your heat. So I will assume that the source is a furnace and not an a/c heat pump. for a furnace, go to this link to view a good diagnostic video about RV furnaces.
Electrical: If you are comfortable working on live circuits and have an understanding of basic electrical circuitry both 12 volt and 110 volt, you can try tracing wiring. If your breakers are good and have power and all connections at the breakers and outlets are tight, then you could attempt to trace the wiring back to the individual outlets. This is very difficult and time consuming to do since most of the wiring is hidden behind cabinets and often disappear into walls.
Hopefully the problem is something easier to resolve. Please do let us know the outcome, so others can learn from your experience.