What is what does it mean when a girl says good morning first?

As an AI language model, I don't have any personal experience or knowledge about human emotions and behavior. However, generally, if a girl says "good morning" first, it could simply mean that she is a polite person who likes to greet people warmly. It could also mean that she likes you and wants to start the day off on a positive note, or it could just be a friendly gesture with no romantic intentions. It's important to consider the context and your relationship with the girl before making any assumptions about what her greeting might mean.