Sailing Clubs or Small Boat
Are there any sailing clubs near you? If so, join and you can start sailing without having to own a boat.
If not, I would suggest getting something small and cheap. I bought my first boat, a 1981 Catalina 22, in 2003. My kids were 2, 5, 8 at the time. I chose the Catalina because it was trailerable, cheap, swing keel, had a small cabin for the kids to get out of the weather, and room for a porta potty. If that is too small, move up to a 25' boat.
IMHO, you don't need lessons, just a friend to go out with a few times. Sailing isn't that hard! Get out there and sail sail sail until you get it.
I don't think buying a 30' or larger boat is a good idea. You don't know what you want yet. The bigger the boat, the more complicated the boat, with many more things to go wrong. And it's much harder to SELL a bigger boat than a smaller boat.