Sacramental preparation, including catechesis, is afforded to anyone desiring such, given he/she is in good standing with the Catholic Church and living in accordance with its precepts. (Attendance and participation at Mass on Sundays and Holy Days of obligation is expected.) The celebration/reception of a requested sacrament can only take place once one has been properly prepared for the particular sacrament, as determined by the Pastor in accordance with the laws and norms of the Catholic Church.
Catechism of the Catholic Church
Part TWO: THE CELEBRATION OF THE CHRISTIAN MYSTERY
Section Two: the Seven Sacraments of the Church
1210 Christ instituted the sacraments of the new law. There are seven: Baptism, Confirmation (or Chrismation), the Eucharist, Penance, the Anointing of the Sick, Holy Orders, and Matrimony. The seven sacraments touch all the stages and all the important moments of Christian life:1 they give birth and increase, healing and mission to the Christian's life of faith. There is thus a certain resemblance between the stages of natural life and the stages of the spiritual life.