The Church generally does not “approve” prayers, except if there’s a whole book of prayers then the book might get certain publishing approvals from the Church.
We are even allowed to make up our very own prayers.
If you are looking for reliable sites for good novenas, then Praymorenovenas.com or EWTN.com have good selections.
I note that the Manual of Indulgences, which is probably beyond the level of how you are praying right now (it’s kind of an advanced prayer activity), does make reference to prayers “approved” by the “ecclesiastical authority” in order to get certain indulgences. In those cases they will usually give examples of which prayers are “approved” and include some in the manual, or a Catholic can use a prayer that has received the Imprimatur/ Nihil Obstat or one that was written by a Pope or by a great saint like Thomas Aquinas, etc. If this doesn’t make much sense to you right now then don’t worry about it. The important thing is that you pray.
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