Actually, if I were you, I would NOT visit the Cambridge club, or any other, on a fireworks/bonfire party....reason being they will all know each other but you would be just another stranger there for the party....
Best thing is to turn up EARLY MORNING - before 9 am, on a weekend when good weather is forecast, and HELP GET THE GLIDERS OUT! That way you can really find out what the locals are like. Furthermore, you will make a good impression.
But if you have not handled aircraft before, ask those in charge for advice; ie, don't push on trailing edge of wings, always walk around wings, never step over them, only one person to hold the wingtip to guide the glider, etc etc. It is easy to damage an aircraft when winkling it out of a crowded hangar. Once it is in the open, you come in handy, learning to hold the wingtip, drive retrieve vehicles, and so on. Always keep your eyes open for airfield traffic, don't walk or drive across approach or takeoff paths, beware of winch cables, propellors, etc.
And at the end of the day, buy your instructor a beer.....