Your classes will be shown as a code something like CL_12Rnf/106 (purely an example).
CL = Clayton campus - This shows the campus you're doing this particular class at. CA is Caulfield and the others will have their own too.
12Rnf = 12 Rainforest Walk - This is an abbreviation for the address for the building your class is at.
106 = Classroom (or whatever type of room) #106 - This is the number or code of the classroom/ lecture theatre/ whatever type room you'll be taking the class. Some might include letters e.g. S1, but essentially this just indicates a room number that'll be written on the door/ near the classroom.
Does this make sense? If you need help interpreting the addresses (this is the part that stumps the most people) or another part of the code, please list an example from your preferences and we can go from there.