She said Im 'one of a kind' what does this mean?

Every girl actually has their own meaning about that, and others well, they'd be really naive to a guy's feelings so it can probably be just a compliment co'z she sees you as unique but it can be possible if you have other proofs like she wants to be with you, she's giving you a special treatment that she does not give to others, she's sad when your not around and all that.