The word apocrypha comes from the greek apokryphos (ἀπόκρυφος), which is an adjective that means private. It is a form of the verb apokryptein (ἀποκρύπτειν), which means to hide away, and is is derived from the combination of apo (away) and kryptein (hide or conceal).
The idea is that the apocrypha books are meant to be read in private, and not used for public sermons or otherwise authoritative teaching. It’s not that they are secret or forbidden; just that they shouldn’t be referred to when deciding public matters of conduct or doctrine.
They are like the notes in a study Bible. The notes in a study Bible are meant for your own private (apocrypha) use. You can quote the actual Bible verses as authoritative, but you can’t quote the notes about those verses as anything other than informative or entertaining.
And, yes, the Bible does contain references to apocryphal writings.
For instance, the New Testament references works that are part of the Apocrypha, such as Enoch (Jude 14) and Ascension of Isaiah (Hebrews 11), but does not cite them as Holy Scripture.
Additionally, there are non-canonical books referenced in the Bible, including the Book of Jasher, which is mentioned in Joshua 10 and 2 Samuel 1, and the Acts of the Kings of Israel, referenced in 2 Chronicles 32.
There are also references to books that no longer exist, such as the Book of the Wars of the Lord, which is mentioned in Numbers 21:14 - although, this may be another reference to the book of Jasher.
https://www.kingjamesbibleonline.org/Apocrypha-Books/
https://scriptural-truth.com/apocrypha_books.html