Do's and don't's of Catholicism?

The short answer to Do's of Catholicism would be:

To Follow The Precepts of the Church:

1. Attend Mass on Sundays and on Holy Days of Obligation.

2. Confess your sins at least once a year.

3. Receive Communion at least once a year at Easter.

4. Observe Days of Fasting and Abstinence.

5. Support the Church.

Pray daily:

Morning Offering, Our Father, Hail Mary, Glory Be, and the Angel of God (more can be added).

The short answer to Dont's of Catholicism would be: Do not do anything not on the list! (that was a joke!) You get the idea.

However, you must know that volumes can be, and have been written, about this very subject. The most important thing is live a Christian life, proclaim the Gospel at all times, and use words when needed.