I think it's very common to meet Catholics who are confused about what the Church requires of her children and what she does not. Do we need to believe that papal encyclicals are infallible or not? Are we only bound to believe what the popes and bishops have declared through ex cathedra pronouncements or conciliar decrees? Must you believe that Mary appeared at Fatima? Does the Church require daily recitation of the Rosary?
Sophia Institute's What Catholics are Free to Believe or Not (2016) is a short, concise guide to answering such questions. Originally published in 1906, I found it to be a trustworthy primer for instructing one in the difference between public and private revelation as well as private acts of devotion versus the precepts of the Church. If you are looking for an in-depth discussion of the levels of authority attached to different papal pronouncements (encyclicals, apostolic post-synodal exhortations, public addresses, etc.) you will need to look elsewhere; but if you want the general guidelines for distinguishing divine faith from pious opinion, then this is the book for you.