Have you been enjoying all the angry parrots in the Duolingo Latin course?
If you're specifically looking for resources on learning Medieval Latin, I can't really help you, since I was classically trained, but a very famous classical Latin course is Orberg's
Lingua Latina, which is basically a series of books written in Latin, beginning with very simple text and then escalating, with all of the grammar explanations also written in Latin. Highly recommended, since one difficulty with classical languages is not developing proper reading skills.
The textbook I used in college was
Wheelock's Latin, which is great for grammar but doesn't really prepare you for reading actual texts in Latin.
As for the Vulgate, I haven't tried to read it (I'm primarily a Greek student these days, so I've been working on the Koine instead), but I imagine that it would be pretty valuable. It's also supposed to be fairly simple Latin, which is always a plus.