Chapter 57 from The Book of Church Order--part of the PCA's doctrinal standards, along with the Westminster Confession of Faith--(a link to such in pdf format can be found here) is titled "The Admission of Persons to Sealing Ordinances".
Children who have been infant-baptised are not to take part in communion:
57-1. Believers’ children within the Visible Church, and especially
those dedicated to God in Baptism, are non-communing members under
the care of the Church. They are to be taught to love God, and to
obey and serve the Lord Jesus Christ. When they are able to understand
the Gospel, they should be earnestly reminded that they are members
of the Church by birthright, and that it is their duty and privilege
personally to accept Christ, to confess Him before men, and to seek
admission to the Lord’s Supper.
Each congregation (represented by a council of elected elders) decides when such a person is ready to received communion:
57-2. The time when young persons come to understand the Gospel
cannot be precisely fixed. This must be left to the prudence of the
Session, whose office it is to judge, after careful examination, the
qualifications of those who apply for admission to sealing
At this time a public profession is recommended but not necessary:
57-4. It is recommended, as edifying and proper, that baptized
persons, when admitted by the Session to the Lord’s Supper, make a
public profession of their faith in the presence of the
congregation. But in all cases, there should be a clear recognition
of their previous relation to the church as baptized members.
So the PCA does have a process of confirmation however it is not necessary public and it is at the discretion of the congregation (via the elders) as to the nature of confirmation - whether classes are required, who will be admitted, whether there will be a ceremony. In practice many churches do require and offer classes for confirmees.