Hannah, is there any kind of yacht club or sailing club on the body of water where you intend to do most of your sailing? If so, what kind of boats are they sailing? Even if you don''t intend to race, I would start there.
In the 14'' category, the Sunfish and the Laser are both boats that have been hugely popular and successful the world over. They are generally intended to be sailed by one person, but can take two. Three would be pushing it.