I need help with this guy i like???! 10 pts first answer?

ya so i like him and we look at each other somtimes. but his facial expressions are plain and i dont know if he likes me or is just looking at me. caz when he looks at me its usually in a crouded group of in the halls at school. so idk what to do and i am really shy and i want to signal him that i like him but i am REALLY scared or rejection. and what if he thinks thats weird or im weird (which im really not) i dont want too creep him out tho. so how do i signal to him without being a looser? thanks. i wnat him to catch on. help me not be afraid of rejection