Cam350 is quite a complex front end system and gerber editing program, what do you want to achieve. Are you just going to read in gerbers and view them, are you going to fully check these Gerbers to an IPC-D-356 net list.
Are you gonna use ODB++?
Are you going to panelis PCB's and do step and repeats in the panel?
Are you going to create multi PCB panels etc etc
There is a lot you can do with the program, so you need to tailor your learning to what you want to achieve.