I can't solve the latter problem of how your family will treat you. What kind of Church are you currently attending?
It depends upon the PCA Church, but you need to begin by regularly attending the PCA Church you are interested in joining. Some require membership classes prior to joining so people get a sense of the Church as well as understanding membership vows.
At some point, you'll meet with the Session (or a subset of Elders appointed). They will interview you about your belief In the Gospel and get a sense for other things about you. They'll probably know you a bit already from time spent. The point of the interview, however, is not to ascertain your theological acumen but whether you understand that you are a sinner and that Jesus is the Savior of sinners and that you understand you are joining a Church, which entails submission and mutual edification. They'll also make sure that you've been baptized because, if you haven't been baptized, then you'll need to be.
The questions you'll be posed after the interview are the vows that you are taking:
Do you acknowledge yourselves to be sinners in the sight of God, justly deserving His displeasure, and without hope save in His sovereign mercy?
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?
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?
Do you promise to support the Church in its worship and work to the best of your ability?
Do you submit yourselves to the government and discipline of the Church, and promise to study its purity and peace?