Hello Jettylady, welcome aboard. There is a lot of good info on the site, as well as good knowledgeable people here to help out. Feel free to post for help anytime in the RV/Camper discussion area, which is also were you can look through previous posts and good info as well.
Your camper is likely equipped with a 12 Volt DC (battery) system. This runs lights, fans (including the furnace blower), the water pump, etc.. This will not run your fridge or AC unit. If you ever do any dry camping, this is handy, so when you dont have power hookups, you can use the batter for the listed above items. You would only get a day or so out of a battery depending on what you used it for, so it needs to be charged if using for longer periods.
The battery will charge from the truck's electrical system, which is the standard automotive 12VDC, when the engine is running. Also, if so equipped with an 110VAC-12VDC converter it will also charge the battery whenever you are connected to power such as home or campground hookup.
The standard for household electricity in the USA is 110 volts, alternating current (110VAC). Since an RV is meant for living in, and thus using some household appliances in, it will typically have a 110VAC system. In most cases, this runs the microwave oven, air conditioner if we had one, refrigerator, lights, etc... You probably also have ordinary household-style outlets in the interior for plugging in anything else you may want to run.
I dont know what amperage your unit is but lets assume 30 amp. A standard 30 amp plug will plug in like any other plug into the right recptacle (not your standard home receptacle). You can buy an adapter plug to convert from 30 amp down to 15 amp, which will allow you to plug in your camper at home, charge batteries, use lights, run fridge etc... I would not try to run the AC unit this way, unless you know you have enough amps from that source to do so.
From there the power goes to a 2 stage converter. At this point some of the power will go to your 110 volt appliances (microwave, Tv). The other part involves your 12 volt system (lights, fans, radio). This works then 110 volt power is supplied to your converter, which charges your batteries, which in turn supply your 12 volt power.
This is a brief overview of things, and if you have more questions about this or others, drop us a line in the RV Discussion area. Good Luck!