Hi and welcome! You're not stupid, just new to Hi-Los.
First, the A/C WILL NOT run on battery power. You have to be plugged in to "shore power", and it needs to be a 20A circuit, minimum. (30A is better).
Then, you MAY have to connect a power cord, usually found in the bathroom so that power gets from the bottom half to the top half where the AC lives. I say "MAY", because my A/C power cord is permanently connected. (I think they went to the permanent connection in later models.)
The A/C will not function on AC power unless the "Master Switch" next to the "Lifting Switch" is in the "camping" position. It also has a center, "neutral" position and a lower, "lift motor" position.
Finally, of course, there's the possibility that a circuit breaker has popped.
Now, the refrigerator is supposed to work on AC, DC or propane. And it is completely "silent", unlike your home refrigerator. What happens is that a heating element or gas flame heats ammonia in a closed circuit causing it to circulate and transfer heat to the outside. It will take about 24 hours for the refrigerator to become cold enough to use after you start it.
When you say it doesn't work, how do you know? If you run the refrigerator on battery power, it will drain the battery QUICKLY, unless the battery is receiving a charge current from the tow vehicle. There is a 30A inline fuse on the DC circuit that could be blown. It is most efficient on propane. It WILL run on AC power from a 15A circuit if your converter is functioning.
And that's the last possibility: Shore power is fed to the "converter", and from there, AC power is delivered to the refrigerator and A/C. If the converter is bad, nothing will work on shore power and your battery will not receive a charge.
I've possibly confused you by now. There is a link to videos on Hi-Lo operation in the forum. Here's a link to the first one:
http://www.hilotrailerforum.com/f49/hilo-video-owners-manuals-youtube-1233/
Glad to have you with us!
- Jack