Apartment

Moving From Apartment To Sailboat?

I was hoping to receive any input from anyone who has lived on a sailboat. Some questions being
which boat is a good liveaboard?
any unexpected expenses?
is it possible on a 28-32′ sailboat to live with a girlfriend or will we just go nuts?
insurance?
how to buy (broker, private sale?)
Anyways any input is valuable for this huge change in my life. I am a hard working 20 year old male looking to put his money into something that will essentially save him money. Thanks folks.