Of course not all tips are helpful.
As far as I can tell, you can only join the scenario associated with the region you are currently in, and then only if you are in the appropriate level range.
So no level 12+ players in Nordland can join a scenario, because Nordenwatch does not allow it, and no level 11 or below players in Troll Country can join a scenario because Stonetroll Crossing does not allow it. If you are the wrong level, you get a message about not being able to join the local scenario.
You also cannot join a scenario queue at all from Altdorf.
And just to top it off, you do not always end up back in the location from which you joined. I’ve ended up back in the war camp half way across the zone from where I joined on several occasions.