The ministers of the sacrament of marriage are the man and the woman who marry; by manifesting their consent and expressing it physically, they receive a great gift. Their consent and their bodily union are the divinely appointed means whereby they become "one flesh". By their baptismal consecration, they were enabled to join in marriage as the Lord's ministers and thus to respond to God's call. Hence, when two non-Christian spouses receive baptism, they need not renew their marriage vows; they need simply not reject them, since by the reception of baptism their union automatically becomes sacramental. Canon Law also recognizes the validity of certain unions celebrated without the presence of an ordained minister. (...) The Church can require that the wedding be celebrated publicly, with the presence of witnesses and other conditions that have varied over the course of time, but this does not detract from the fact that the couple who marry are the ministers of the sacrament. Nor does it affect the centrality of the consent given by the man and the woman, which of itself establishes the sacramental bond. (Amoris Laetitia #75)
The most profound thing about a Christian marriage, however, is the couple's knowledge: "We are a living image of the love between Christ and the Church." [Catechism of the Catholic Church #1644-1654,1664] (Taken from YouCat)
Contact your local parish for information about celebrating the Sacrament of Marriage.