Well lucky you, you're now friends with a great conversationalist.
Well, first of all, be yourself. Just, ask how the person's day was, crack a joke, be yourself and show the person you're a confident person. Little tip: Girls LOVE Confidence. If there's a girl you like, as more than a friend, take a chance, talk to her. Show her you care about her, Give her attention. I gave my current girlfriend loads of attention during class... You see where I'm going with this. I can't stress enough, BE YOURSELF. Kay?