Tutorials
To get started, you can follow the tutorials in this section. They are designed to help you understand how the package works, first without getting into the specifics of colliders (only concepts on a dummy example), and then with a focus on how to use it for an actual collider configuration followed by tracking.
However, if you want to start doing tracking studies right away, you might want to go straight to the case studies section.
In any case, many tweaks and details are also explained or re-explained in the case studies, so you should definitively check them out at some point.