Well, when a person has no sympathy for other people/they don't really care about other people's feelings, we may call them 'hard faced'. Yes, a hard faced person will often be the one not smiling. Streets are split into sections called blocks so that it is easy to find certain locations. To 'be new on the block' means that a person is new on that specific section of the street. He/she just moved into that neighborhood. Paperback boy-I'm not sure of that definition. I'll let someone else answer that. 'A slate so clean' means that he was pure and innocent, he hadn't done many things wrong. Yeah, I think 'heart-shaped queen' is close to meaning 'sweetheart'. "It" refers to 'being a paperback girl'. We usually say, 'before it was cool,' but just for teaching purposes, I'll write the sentence another way to get the main idea: "You were a paperback girl before being a paperback girl was cool." Ok. I hope that helps at least a little bit. :)