I would suggest if you live in or near a major city, a Catholic bookstore is the place to visit. A Catechisim would be a good place to start and the store can make recommendations.
If you are asking the question on why the appeal, I think the comfort and the enduring nature of the Church is my appeal — but it would differ for each person. Also the structure.
As for hierarachy, that might be a rather long explanation because the Church is a huge organization. The Pope is the absolute head of the Church. On questions of faith, he is infallible. There are levels of hierarchy below the Pope — starting with the Holy See (or the Cardinals).
There are many official sites which explain that the Church is divided into what’s called Archdioceses, headed by an Archbishop (who may or may not be a Cardinal) and then dioceses headed by a Bishop. There are holy orders and religious orders. This is a very brief explanation.
I think if you are interested in knowing more, you might want to pursue this through some official readings from an official Catholic bookstore.