Yes, it is required. You’d take at least 4 semesters of it. A commonly recommended book is “A Primer of Ecclesiastical Latin” by…somebody…Collins. A good, Latin dictionary (preferably with an ecclesiastical focus, such as the dictionary put together by Stelten…although his is not quite comprehensive enough) is also a must.
Canon Lawyer Ed Peters has further information here:
canonlaw.info/catholicissues_ecclatin.htm
Dan
