Talking to a guy...

Well I always get really nervous and never know what to say...
How can I just chill out and chat normally to guys!!!

Don't think about it. I just realized that I didn't think about it and talk to him as it were any of your girlfriends (well minus the girly talk stuff). Let loose. Laugh and joke a little first. I have always found it easier to find a good joke, tell it to your friends first (as a practice) and then tell it to him. It is a good sign when a girl gets a guy to laugh. That is your ice breaker. Then keep practicing, and don't let your thinking about what he thinks get in the way.

Don't worry so much about what they think about you...