Short answers, pulled from the story.
The Catholic Church claims to be the living continuation of Jesus Christ on earth, known as the Mystical Body of Christ. It is the one, holy, catholic, and apostolic community founded by Jesus and governed by the successor of Peter and the College of Bishops. The Church teaches that it possesses the fullness of the means of salvation and exists simultaneously on earth, in Purgatory, and in Heaven.
The seven sacraments instituted by Christ are Baptism, Confirmation, the Eucharist, Penance, the Anointing of the Sick, Holy Orders, and Matrimony. The Eucharist is considered the source and summit of the Christian life where bread and wine are transubstantiated into the true body, blood, soul, and divinity of Christ. This sacrament makes the single sacrifice of the Cross present again in an unbloody manner.
The Holy Trinity is the belief in one God in three distinct persons or hypostases: the Father, the Son, and the Holy Spirit. The Father is unbegotten, the Son is eternal yet begotten of the Father, and the Holy Spirit proceeds from the Father and the Son. Each person is considered to be fully God, and the Son, Jesus Christ, is true God and true man.
Catholic soteriology teaches that eternal life is a free gift of God and that the crucifixion of Jesus is an atoning sacrifice which takes away the sins of the world. There are three states of afterlife: Heaven, Purgatory, and Hell, with Purgatory being a temporary state of purification for those who are saved but not free enough from sin to enter directly into Heaven. The Church teaches that no one is condemned to Hell without freely deciding to reject God's love.
Men become bishops, priests, or deacons through the sacrament of Holy Orders, and the Church ordains only males following the example of Christ and Apostolic tradition. In the Latin Church, only celibate men are ordained as priests, while the Eastern Catholic Churches ordain both celibate and married men. After ordination, marriage is not allowed, and a married priest whose wife dies may not remarry.
Catholics venerate Mary with titles such as Blessed Virgin, Mother of God, and Queen of Heaven, giving her special honor above all other saints. Catholics do not worship Mary but honor her as mother of God and as a spiritual mother to each believer in Christ. Prayers and devotions asking for her intercession, such as the Rosary and the Hail Mary, are common Catholic practice.