Necessary minimum requirements of Catholics

You can found the Precepts in the Catechism. They are broken into five Precepts.

1. (“You shall attend Mass on Sundays and holy days of obligation and rest from servile labour”) requires the faithful to go to mass in a church every Sunday as well as other specific days of the year. You should also rest and avoid working on these days as well.

2. (“You shall confess your (serious) sins at least once a year”) You should try to confess any sin you commit as soon as possible if it is a Mortal sin and weekly if it is a Venial sin. 

3. (“You shall receive the sacrament of the Eucharist at least once during the Easter season”) You should try to take the Eucharist more often if your soul is clean of sins.

4. (“You shall observe the days of fasting and abstinence established by the Church”) ensures the times of penance which prepare us for the liturgical feasts and help us acquire discipline over our heart.

5. (“You shall help to provide for the needs of the Church”) This means donating money or time to your locate church. The amount of either does not matter it is simply the doing of it.

What the differences in unbelievers are.

This list is in the Baltimore Catechism #3, Lesson 30, Question 1170. 

Atheists - Who deny there is a God.

Deists - Who admit there is a God but deny that He revealed a religion.

Agnostics - Who will neither admit nor deny the existence of God.

Infidels - Who have never been baptized, and who, through want of faith, refuse to be baptized.

Heretics - Who have been baptized Christians, but do not believe all the articles of faith.

Schismatics - Who have been baptized and believe all the articles of faith, but do not submit to the authority of the Pope.

Apostates - Who have rejected the true religion, in which they formerly believed, to join a false religion.

Rationalists and Materialists - Who believe only in material things.