Short answer:
Yes, it's a common practice to have a fire, and for jumpers to sit around it, often (not always) drinking 'adult beverages', hanging out, swapping stories (often, but not always about jumping) and socializing.
Longer answer:
One of the coolest things about jumpers and jumping is the overall equality of the sport.
It doesn't matter who you are, what you do for a living, how experienced you are, how old or young. If you have what it takes to gear up, get on the plane and jump out, you're "one of us".
One of the places that becomes most apparent is 'around the bonfire' after jumping is done (another is weather hold shenanigans).
You might end up sitting next to a 'new guy' who has yet to get through AFF. You might end up sitting next to a world record holder, who has multiple medals from national competition.
The stories shared around the bonfire often start of with "No shit, there I was, thought I was gonna die". Not all are true.
But there are LOADS of lessons that you can learn. Mostly learning what not to do.
As Rob noted, 'beer dues' are often paid off around the bonfire.
There are actual written 'beer rules'. Primary one is that anytime you accomplish something for the first time, you owe a case of beer. The idea is that you share those beers around the fire, and more experienced jumpers will ask 'what did you do', then share some stories of their 'firsts'.
Beer for the bonfire is also 'paid' in fines for landing area violations. Somewhat of the same concept.
It's a good way to get to know other jumpers around the DZ, people you will be jumping with if you are a regular at that DZ.
It's a good way for people to get to know you.
It doesn't matter if you drink or not. Personally, I don't drink anymore.
But I still pay my 'beer fines', hang out around the fire, enjoy the company and stories, share a few of my own, and have a good time.