What happens to a human after he dies according to the Catholicism? A good answer should reference official church sources.
In the Penny Catechism Q 332. asks, "What are the four last things to be ever remembered?"
The answer is:
The four last things to be ever remembered are Death, Judgment, Hell, and Heaven. [cf. Ecclus 7:36].
Therefore after death the body turns to dust and the soul of man is judged1.
The soul of man then goes to hell or to heaven (perhaps via purgatory) and awaits the resurrection of the body so that each one may receive good or evil, according to what he has done in the body. [cf. CCC 366.]
1. cf. Heb 9:27 (RSVCE).
Please see also: ARTICLE 12 "I BELIEVE IN LIFE EVERLASTING" of the Catechism of the Catholic Church.
Immediately at death the soul is judged by Jesus Christ, this is called the particular judgment. If you died a Baptized Catholic in a state of grace you will go to Purgatory or Heaven, otherwise you will go to Hell or Limbo of the children.[see notes] A soul in purgatory will suffer there for a time but ultimately end up in Heaven.
Then at the end of the world, the final judgment takes place and the soul is reunited with the body in its glorified form for the saints or in its monstrous form for the Damned. The glorified body has four attributes: brilliance, impassibility, agility, subtility. The Damned will not be able to move in Hell and they will be tortured day and night forever and ever. More in the link.
Notes: People in the Vatican II sect believe anyone can go to Heaven no matter what their religion or actions in life.
Teaching of the Church
Pope Eugene IV, Council of Florence, “Cantate Domino,” 1441, ex cathedra:
“The Holy Roman Church firmly believes, professes and preaches that all those who are outside the Catholic Church, not only pagans but also Jews or heretics and schismatics, cannot share in eternal life and will go into the everlasting fire which was prepared for the devil and his angels, unless they are joined to the Church before the end of their lives; that the unity of this ecclesiastical body is of such importance that only for those who abide in it do the Church’s sacraments contribute to salvation and do fasts, almsgiving and other works of piety and practices of the Christian militia produce eternal rewards; and that nobody can be saved, no matter how much he has given away in alms and even if he has shed blood in the name of Christ, unless he has persevered in the bosom and unity of the Catholic Church.”