Hi Adrianna,

Thanks for your thoughtful and respectful inquiry—it’s refreshing to see an author wanting to depict religion accurately and thoughtfully. That's a good question. Your request involves rather unique requirements; you want something focused, not on doctrine (that would be the Catechism of the Catholic Church), but on the structure of the church and perhaps, we might say, the external trappings.

For a solid foundation, I’d recommend a few books that cover Catholic practices, structure, and customs without necessarily diving deep into belief or doctrine:

• "Catholicism for Dummies" – great visual and structural overview.
• "The Catholic Source Book" – full of terms, customs, and traditions.
• "Interview with an Exorcist" – gives a real Catholic view of spiritual warfare without hype.

You’re also welcome to ask specific questions along the way. I help answer questions at AskACatholic.com, and we’re happy to support respectful portrayals of faith in fiction.

May I also recommend getting an account with ChatGPT.com, an agentic AI that is really good about answering questions and tutoring you on subjects like this. As you go along, you can interactively ask questions, and it will explain things. You can present parts you've written and ask it to validate things. You can have it write extended tutorials on topics. While occasionally it hallucinates — you will want to have a knowledgeable Catholic proofread your finished novel, which is a good idea anyway — especially for topics like this, it is very reliable. 

God bless your writing journey, and good luck with the novel!