My best advice
for you would be, start poking around boats, any and all boats and get as much time on them as possible, start hanging at marinas
and offering to help with anything an owner might be doing, you will learn alot that way and get to see how many many boats are put together, and will often get to sail on them. Look at what boats are out there and figure out what you like and more importantly what you don't like. Then when you start looking for YOUR boat
, take the smallest you can be comfortable living in, and you will have an idea of what you want/need in the boat
and if she has the space to put all your things plus you, and will carry you safely to where you want to go, that's your boat.
To me the big small debate is personal, to me a 45 footer is a BIG boat, I have a 30 footer that is plenty big enough for me but for some she will be tiny. So figure out what you want in a boat and go from there. And remember as size goes up cost dramatically goes up, so find the best compromise for you and go with that.
As far as learning
how to sail there are many ways to learn to sail, some people grew up sailing, others never sailed a day in their life before they set off and learned as they went ( the later not recommended) still others learn by messing about on small boats, and others still on other people's boats and in sailing courses, which if you have little to no sailing experience would be a great idea, and yet others still eschew sailing altogether and buy a power boat
, their still on the water
, still living the dream as it were, just not sailing.