I disagree with the suggestion that you jump ...
into a 45 foot vessel, trawler or sailing. I've heard of singles and couples living on a 28 foot sailboat. A little cramped but ours had a two burner alcohol stove, hot and cold running water, private head with shower, furnace, etc. We began with making a list of the things we wanted on our first boat, an H28. We found one at the price we could afford and had it for three years before upgrading to our current boat.Spend time on a list of how you want it equipped and agree on it. Visit your local marina to check out boats that are for sale. We went to a few boat shows, too. Good luck on your new adventure.Terry