How mandatory is class attendance?
Some classes are mandatory, others aren't. However, the ones that are not absolutely mandatory are still the kind of classes you are "Highly Encouraged" to attend.
Once you start, you will get the hang of which ones you can miss and which ones you need to show up for. It's a little tough to explain online and Big Brother is always watching
Also, if class attendance gets ridiculously low they might take away some privileges, so be cognizant of that.
Once you get assigned your big buddy, he/she will be able to tell you a little more about this.