What to say online/in person to a girl I like

Hi so I've always had a problem thinking of the right thing to say, I'm so paranoid that what I say will be a turn off. There is a really cute girl in my small town on POF I'd like to message. Even out of all the girls I've seen in Chico and Sacramento, she is particularly cute. I'm trying my best to be myself by saying, "Wow your too cute for this town, what brings you here, family?" or, "Hey I just wanted to say I really like you and would like a chance at a date with you." So highschoolish right? Like I said I can't think of anything. You should see how I am with pretty girls in person, I totally lock up and am at a loss for words nervous beyond all belief. I feel like I'm looking for some guidelines to come up with something to 'be myself' and not sound repetitive. Due to a disability and alcoholism in the past, I never had the opportunity to approach someone.