I'm not a pilot but worked in the industry for many years. Because of that, I know a lot of pilots and some who are even 737 type-rated. Some have taught me a few things, but what was really interesting was that a former client of mine was a flight school that had a full motion 737 simulator (believe it or not, a professional version of MS Flight Simulator plus a ton of add-ons was the software!). IIRC, it took about 10 PCs (each running specific modules) connected together with Firewire (yes, firewire!) to operate it. It was FAA certified as a real simulator. Anyways, I played in that quite a bit and in a pinch I might be able to pull it off (albeit, it's been several years so I probably forgot a few things). And obviously with guidance over the radio, as various procedures and calculations and limits I would not know. Of course being in the real aircraft with the stress involved would be a factor that one has to consider, too....
As for radio frequencies, again, being in the industry previously (but not a pilot), I am aware of the types of frequencies, etc. A google search of the approach plates, if you could not figure out how to use the electronic versions on the aircraft, it would be pretty easy to figure out the proper ATC frequencies. (provided you can get an internet connection of course). You can also squawk the emergency code on the transponder to get attention (I forget the code, but it's the same worldwide). Squawking the code is as simple as dialing in the 4-digit code in the proper place and (I think) you have to press IDENT. That would at least get ATCs undivided attention.
For the record, I've also flown in a Learjet-55 simulator's right seat a couple of times, with a real lear pilot (who used to be my business partner) in the left seat and also a flight instructor (who was a friend) at the trainer's console... At one point I was considering getting a pilot's license but never got around to it.