The old Baltimore Catechism recommends…
486. What are the prayers that every Catholic should know by heart?
The prayers that every Catholic should know by heart are: the Our Father, the Hail Mary, the Apostles’ Creed, the Confiteor, the Glory be to the Father, and the acts of faith, hope, charity, and contrition.
487. How do we usually begin and end our prayers?
We usually begin and end our prayers with the sign of the cross.
To that list, I would add the Grace Before Meals prayer and the Grace After Meals prayer, below.
The Sign of the Cross:
In the name of the Father, and of the Son, and of the Holy Spirit. Amen.
The Our Father:
Our Father, who art in heaven, hallowed by thy name. Thy kingdom come; thy will be done on earth as it is in heaven. Give us this day our daily bread; and forgive us our trespasses as we forgive those who trespass against us; and lead us not into temptation but deliver us from evil. Amen.
The Hail Mary:
Hail, Mary, full of grace, the Lord is with thee; blessed art thou among women, and blessed is the fruit of thy womb, Jesus. Holy Mary, Mother of God, pray for us sinners, now and at the hour of our death. Amen.
The Apostles’ Creed:
I believe in God, the Father almighty, creator of heaven and earth. I believe in Jesus Christ, his only Son, our Lord. He was conceived by the power of the Holy Spirit and born of the Virgin Mary. He suffered under Pontius Pilate, was crucified, died, and was buried. He descended into hell. On the third day he rose again. He ascended into heaven, and is seated at the right hand of the Father. He will come again to judge the living and the dead. I believe in the Holy Spirit, the holy Catholic Church, the communion of saints, the forgiveness of sins, the resurrection of the body, and the life everlasting. Amen.
I confess to almighty God, to blessed Mary ever Virgin, to blessed Michael the archangel, to blessed John the Baptist, to the holy apostles Peter and Paul, and to all the saints, that I have sinned exceedingly in thought, word and deed, through my fault, through my fault, through my most grievous fault. Therefore I beseech blessed Mary ever Virgin, blessed Michael the archangel, blessed John the Baptist, the holy apostles Peter and Paul, and all the saints, to pray for me to the Lord our God.
The Confiteor at the Mass:
I confess to almighty God and to you, my brothers and sisters, that I have greatly sinned, in my thoughts and in my words, in what I have done and in what I have failed to do, through my fault, through my fault, through my most grievous fault; therefore I ask blessed Mary ever-Virgin, all the Angels and Saints, and you, my brothers and sisters, to pray for me to the Lord our God.
The Glory Be to the Father:
Glory be to the Father, and to the Son, and to the Holy Spirit. As it was in the beginning, is now, and ever shall be, world without end. Amen.
The Glory Be to the Father in the Liturgy of the Hours:
Glory be to the Father, and to the Son, and to the Holy Spirit: as it was in the beginning, is now, and will be forever. Amen.
Act of Faith:
O my God, I firmly believe that you are one God in three divine Persons, Father, Son and Holy Spirit; I believe that your divine Son became man and died for our sins, and that he shall come to judge the living and the dead. I believe these and all the truths that the holy Catholic Church teaches, because you have revealed them, who can neither deceive nor be deceived.
Act of Hope:
O my God, relying on your almighty power and infinite mercy and promises, I hope to obtain pardon for my sins, the help of your grace, and life everlasting, through the merits of Jesus Christ, my Lord and Redeemer.
Act of Charity:
O my God, I love you above all things, with my whole heart and soul, because you are all-good and worthy of all love. I love my neighbor as myself for the love of you. I forgive all who have injured me and ask pardon of all whom I have injured.
Act of Contrition: (prayed immediately after repenting and later during Confession)
O my God, I am heartily sorry for having offended you, and I detest all my sins, because I dread the loss of heaven and the pains of hell; but most of all because they offend you, my God, who are all good and deserving of all my love. I firmly resolve, with the help of your grace, to confess my sins, to do penance, and to amend my life. Amen.
Grace Before Meals:
Bless us, O Lord, and these your gifts, which we are about to receive from your bounty, through Christ our Lord. Amen.
Grace After Meals:
We give you thanks, almighty God, for all yours benefits, who live and reign for ever and ever. Amen.
Also, two helpful booklets (PDF) on prayers and spiritual habits from CatholiCity.com:
Seven Daily Habits for Faithful Catholics
- The Morning Offering. (Also see Morning Offering prayer in the Prayers booklet, below)
- Fifteen minutes of silent prayer.
- Receiving Holy Communion. (Also see Spiritual Communion Prayer in the Prayers booklet, below, since you watch Mass on television and are not yet officially Catholic)
- Fifteen minutes of spiritual reading, especially the New Testament.
- Pray the Angelus. (Also see The Angelus in the Prayers booklet, below)
- Pray the Holy Rosary. (Also see How to Pray the Rosary in the Prayers booklet, below)
- Examination of Conscience at bedtime.
Powerful Prayers Every Catholic Should Know