The best way to get acquainted with WeBWorK is to go ahead and start using it. Since you are not penalized for wrong answers, there is plenty of room to experiment and get adjusted. The initial set of problems is mainly review, so you should also treat it as WeBWorK orientation. You may also wish to practice or to experiment with any sections marked "not for a grade."
Please refer to the WeBWorK guide for more on how to operate WeBWorK: WeBWorK Guide.
The following link is useful, too: Functions That WeBWorK Understands. It goes over the basic syntax of WeBWorK.
WeBWorK is a web-based homework system designed at the University of Rochester. The main WeBWorK site at the University of Rochester can be accessed by clicking on this link.