Your goal with this preparation is to get familiar with three different 3D environments so that you are ready to discuss their purpose, features, effectiveness and shortcomings during the class. You will not receive specific questions ahead of time, instead, you should let your own sense of curiosity and research guide you through these experiences. Make sure you put yourself in the shoes of an actual “user” and spend enough time with each system to know what it is like to use it for its intended purpose.
Please note that a couple of these will require a Windows machine, so you may have to use one of the computer labs in the school, or do this with a friend that has such a machine.