So, you all meet in a bar and decide to start adventuring together...

[Kwitchit]

WotC's free starting module "A Dark and Stormy Knight" (available on the website) has the PCs all take shelter from a thunderstorm in the same tomb entrance in a hill. There's a local custom called "stormpeace" which stops intelligent beings attacking each other while sheltering from a storm. So, you have them all in the same place, not killing each other, and hopefully talking. Then the door to the inside of the tomb bursts open...