Do remember to ask questions or investigate of your character is a cultural Catholic as well as a religious Catholic. Depending on where your character lives and how the upbringing went, that might influence their actions as well.

Good luck on your journey! I wish I could help more, but I've only got Catholic relatives and friends and gone to Catholic weddings. However, my husband is from a heavily populated Catholic area so he seems to know a bunch about it. (Did you know the Pope almost went to Dubuque, Iowa during WWII? Dubuque also has seven hills like Rome. So werid.)