Thoughts on Westminster Confession of Faith, articles I.7-8, which you can find here.
Some parts of the Bible are hard to understand or obscure. But you don’t have to be a scholar or genius to understand its main message of salvation through Jesus Christ. We can put the Bible into the hands of the average man on the street, with confidence that they will be able to understand it. You don’t have to know Greek and Hebrew or have a seminary degree. This is called (ironically) the perspicuity or clarity of Scripture. Ironic, because few know what perspicuous means, so it is NOT clear!
Speaking of Greek and Hebrew, the Bible in the original languages is inspired and inerrant. Translations are not infallible, but they should be done so people can have the Word in their own language. The original texts are preserved in their “essential purity” as A.A. Hodge puts it. There are variants in the many texts we have, so some scribal errors have slipped in along the way, but nothing major or that can’t be sorted out to know what God has told us.