http://www.pcaac.org/BCO 2010 Reprint All.pdf
Presbyterian Church in America
Book of Church Order
Chapter 57
The Admission of Persons to Sealing Ordinances
57-5
(All of) you being here present to make a public
profession of faith, are to assent to the following declarations and
promises, by which you enter into a solemn covenant with God
and His Church.
1. Do you acknowledge yourselves to be sinners in the sight of
God, justly deserving His displeasure, and without hope save
in His sovereign mercy?
2. Do you believe in the Lord Jesus Christ as the Son of God,
and Savior of sinners, and do you receive and rest upon Him
alone for salvation as He is offered in the Gospel?
3. Do you now resolve and promise, in humble reliance upon
the grace of the Holy Spirit, that you will endeavor to live as
becomes the followers of Christ?
4. Do you promise to support the Church in its worship and
work to the best of your ability?
5. Do you submit yourselves to the government and discipline
of the Church, and promise to study its purity and peace?
The short answer is, yes you can attend.
You can be a regular attender (before membership) indefinitely which includes many, but not all the privileges of membership. Members vote, serve on committees, are subject to formal church discipline, etc.
But, God takes these things very seriously. Attendance ought be with the vows of membership in mind, and not taken casually. The more you know (biblically), the more God holds you responsible to believe and act in accord with that.
As far as doctrine, a member in the PCA agrees to peaceably study the church's doctrine (that's the "peace and purity" of point 5.), which will include things like covenant theology, covenant community and covenant families, and infant baptism.
If you are firmly convicted of believers only baptism and clearly against infant baptism, you are not going to be comfortable in a PCA church for long. It does not seem you could in good conscience take the membership vows in that case, you would need to at least be heading in that direction.
But if you are open to learning about it, think there may be a biblical case for it, by all means attend, pray, and study.
In the PCA, as a biblical reformed denomination, is confessional. That means there is doctrine we confess because we believe it is a faithful summary of God's Word. If you can attend and serve in that framework, you will be welcomed as you commit to serving Him and His people.