In your situation, I believe your best friend/teacher will be the internet. All of the RV components...stove, toilet, heater, etc., are made by only a few companies. Look for data plates attached to the items to find name, model, etc., and search on the net for help on them. However, given the age of your unit, information may not be available, BUT, most things like the stove, toilet, etc., still operate in a basic manner. Certain things have changed due to the influx of computers and digital displays, but the basics still work the same way. A stove still needs propane, on/off valves/a source of ignition, and so forth. A toilet needs water, control valve, sewer hookup, etc. I also think when you are asking for help, pick one item at a time. In other words, ask about the heater or the stove or whatever. A generalized, "I need help to make things work" is a hard question to answer. And will probably not find too many answers/help since it is not specific enough. Good luck.
