If there is some structure adhered to, and all occupants of vehicles wear appropriate protective clothing, then there should be no issue with a 'Sighting lap'
a Sighting lap is a low speed crawl of the circuit, designed to help you identify braking points, turn-in points and hazards / anomalies etc.
a Sighting lap is NOT a warm-up lap, a hot lap or any other excuse to pedal hard with 4 mates in the car.
if you want to do race speeds with passengers, then the circuit manager will kick your backside off the track so swiftly you won't ever be coming back.
It's very basic OH & S. much more risk with multiple people. This is why it's banned at every circuit.
Don't wreck it for everyone else by behaving badly. There are track rules, and people who don't abide by them are simply told to leave the circuit. I've seen it happen more than a few times.... people get all silly or hot headed, and wreck the event for everyone.
Follow the rules, and everyone will have a ball, I can promise you that.
Also.... make sure everyone who brings an accomplice brings a camera. pictures are essential!
after all.... everyone wants bragging rights at the end of the day