If parents wish to have their child (either infant or minor charge) they, themselves, must be practicing Catholics [if one of the parties are not Catholic, there is noobligation on their part to attend Mass.]
They must also promise to raise and educate their child in the way of the Church.
They must have received the Sacrament of Confirmation
Their marriage must be a valid marriage, recognized by the Catholic Church.
[[NOTE: Only one Godparent is required to be (a practicing) Catholic. The other individual must be a baptized, "Trinitarian" Christian ]]
If an Adult wishes to be Baptised they must go through a process called the Rite of Christian Initiation. RCIA.