is it just a camp in field ,with lots of drinking
For a very small rally ie <100, yes, but it's the quality that makes the rally. Grand peeps, larf a minute banter, and some decent beer!
Bigger rallys provide more facilities and invite traders.
It's always useful to have a pub nearby; warm, dry, loos, food, and of course
Rideouts are sub-divided according to ability and experience, speed, destination etc.
So there is not a 'mass' rideout, although meetups can be arranged.