There’s a very similar post below yours with some discussion and links. Many of these questions would be too long to answer here. I suggest you do some research using official Catholic sites and get a Catholic authorized Catechism. If you live in or near a major city, there is certainly a Catholic bookstore near you.
As for the Vatican; they have their own site.
As for the hierarch of the Church and how it’s structured:
There are also online bookstores: I only recommend this one since I’ve been there. It’s by no means exclusive.
A moderator and someone more knowlegeable can provide you with additional information. But I would start with a Catechism first.
If you have been introduced to the Catholic Church, then you might attend Mass or already have. Of course, you cannot yet receive Communion, but if after reading and regular attendance, you might want to speak with a priest about religious instruction — if you decide to proceed. The answers on the saints and scripture will be brought up there.
What you should know is that not all readings and sites are official. Beware of any site which might pretend to be Catholic, but is not. One of the posters here can also link you to other sites and forums, but from my own experience, that might be for down the road a bit as you become more familiar. Some of what you are looking for might be found in the “Core Beliefs” section of this site. There is a section on the Bible or Scripture.