I want him to like me/flirting help!?

Ok, this guys sits behind me in two cles, and constantly stares. Now, I don't know if that is a good thing, but anyway, he constantly looks at me, and sits at the very edge of his seat in homeroom and stares. Also, whenever (very few times) I say something to him, he perks up. But...he is really kinda opposite of me. Meaning, he is very well...immature and kind of a cl clown type. I am rather quiet, but still love to laugh and am up for fun. I really think he seems to like me. I don't know. I've barely said more than 2 words to him. How can I flirt/ talk to him? I am so bad at this, and like I said, I am quiet, and to top things off..I've never had a bf. And please don't stay, start up a convo or ask him out...how do I do that, considering I'm probably not the type of girl he'd go for. But I like him! HELP! And does he even like me? He never says anything..just stares.