In most PCA churches, you only have to be able to subscribe to the Confession of Faith if you serve as an ordained officer. (Some extend that to other leadership positions and to adult Sunday School teachers).
I would recommend that you read through the Westminster Confession of Faith and its scripture proofs. (Do a keyword search to see the series posted by Alex Murphy). That’s the OPC version, but it is substantially similar to the PCA version.
And, remember, Calvin himself would probably have had to have taken some exceptions to the WCF.
I used the keyword WCF to mark each entry, although you may find it easier to use this post to locate all the threads.