Hello! Sorry to necro an old thread but I'm in a similar position as you and I wanted to share what's been helping me out! "The Essentials of Living Aboard a Boat: The Definitive Guide for Liveaboards" by Mark Nicholas.
It's a really intense, thorough breakdown of basically everything you need to know to get started. Boat lingo obviously, but specifically the kind you see in boat ads. Caretaking, how to handle weather, climate controls, how to read navigation. Fantastic primer on all these things.