Many boys tend to start talking about themselves when chatting, going on about how hard they work at their jobs, how outstanding they are, and so on. During a date, the focus of the conversation should be on the other person—specifically her interests—rather than on yourself. You can share some of your own experiences and life stories, but the emphasis should be more on her.
However, focusing the conversation on her does not mean you should keep prying into her nonstop. This is a date, not an interrogation. Therefore, you should also chime in with your own experiences and life from time to time to help her gradually relax.