Buying a car in Australia

Hello! I’m new here! A few weeks ago I moved to Australia. Now a vehicle purchase is on. I will look at two models on Friday. Once a Land Rover Freelander, V6, Bj 2002, KM 120,000, checkbook maintained and once a Land Rover Discovery LS BJ 1998, 3.9 liters, KM 193,000, checkbook maintained. Basically I only have one question for both vehicles. What do I have to pay attention to in order not to land a wrong purchase? Thank you.