I think for the first one the church wants us to. Attend church every sunday and listen to the word of god and don’t do any labour intensive work. Go to confession and tell God about your sins so he can forgive them. Over easter season you must take eucerisht at least once. When the church wants you to fast you must follow those rules and must restrain yourself from indulging food. If the church need help you should lend a hand and help with whatever the church needs.
I find it interesting that people used to pay tithe with crops or different agriculture things instead of money. And how that you are supposed to avoid communication with the excommunicated.
Holydays of obligation is every Sunday Christmas day and feast of mary mother of god.