I was in a similar situation as you when I first decided I wanted to live aboard (though cruising isn't in my medium-term plans). I had never set foot on a sailboat before, but I was pretty sure I wanted to do it. I took ASA 101 and 103 with the Maryland School of Sailing and Seamanship. I took the 8-day liveaboard class in Virgin Islands both to learn how to sail and to get some experience with living on a boat. Also it was an awesome vacation. I highly recommend it. I came back, and I immediately got myself a boat broker and started looking.
1979 Gulfstar 37 Laissez Faire