The NSW HPT is 15 short film clips of real traffic, sat at a service centre for $58 an attempt. You touch the screen when you would slow down, overtake or turn, and not at all when it isn't safe. If you're under 25, you can sit it after 10 months on your Ls. Below are the rules from nsw.gov.au, then a free trainer for the one skill you can drill here: timing.
What nsw.gov.au and the Hazard Perception Handbook say about the real test:
The official advice is to prepare by downloading the Hazard Perception Handbook, brushing up on safe driving behaviour, doing the Safer Drivers Course, and getting as much driving experience as you can. Bookings and current fees live on the NSW Government's HPT page.
Each scene plays out in real time. Read the instruction, watch the scene develop, and click RESPOND (or press space) at the moment a careful driver would act. You get one response per scenario. Respond too soon and it scores as too early, or as not safe if you'd pull into a gap that isn't there. In one scene the safe answer is not to respond at all.
A simulator trains your eyes; an instructor trains your habits. After the HPT comes the driving test on real roads, and that's what an instructor gets you ready for.