A boy to like me?

He is in my homeroom, he is just my height, and super nice, but it is the fourth week of school and he told me at homecoming "hey your in my cl right" so he is just now noticing me, my best friend is a total flirt, but she doesnt like him, he flirts back with her all the time, I can never find the right thing to say to him, he is the kind of boy you can have a real conversation with, when he said that to me at homecoming I just pretended I didnt hear him because I did'nt know what to say, I need some conversation starters, and some flirty lines! It would help if I had some confidence too.