Hello,
I would recommend looking over the following guides as well, they helped me get started with CAS.
They provide insight on including dependencies when building CAS as well as example configurations. They also provide insight to building a CAS client/service provider so you can test your instance. Both of those guides involve some form of LDAP/AD authentication and multifactor authentication so they might not align with your chosen form of authentication but they can help clarify the documentation (
https://apereo.github.io/cas/6.6.x/).
Other than that, if you include some more details about the problem you are experiencing such as the version of CAS, modules/dependencies/technologies you're using, and errors from your log file then someone here might be able to help you with the specifics.