All anyone needs to do to keep up on when scenarios occur (since they happen about 3 times per year) is, every couple of months, check any one of the following: ahevents.org, the calendar, the "Scenario General" forum, or the "Special Events General" forum. Or every couple of months, ask in the Main Arena, "Hey, anyone know when the next scenario is?" There usually is at least someone around who will know if a sceneario is announced.
I suppose we could send someone over to your house, though, to make it especially easy. Maybe a swimsuit model in a skimpy bikini!
(We'd probably need to have him shave his hairy back first, though.)
However, even for those who register, scenarios are not a good fit for people who will not fly if they don't get a particular aircraft. It's too hard for a CO to deal with that when having 80-120 people and a mix of aircraft to sort out (among the various other duties of the CO).
If you do need to fly a particular aircraft or you won't fly at all, please do not register for scenarios, but instead do just as was done: show up as a walkon, see if the aircraft you want is available (often times they are -- just not in cases where there are 4 of them for the whole side), then politely leave if not. That is exactly the right thing to do in that case.