Jkid1 - welcome to the forum. It would help to know how old you are.
But some general advice would be: How would you start up a conversation with a guy you didn't know. If you are talking about a specific girl, you must have something in common or you would not be aware of her. Start with that. If you know her from school ask about her classes or her outside activities. If you know her from church - the same thing - ask about something related to church. "Hey, how you doing" is always a start.
Just remember she is probably is has some of the same problems talking the opposite sex as you do, so don’t worry too much about making mistakes.
