When I walk down the hall to my class I lock eyes with the same guy,what does this mean?

I would start my saying hi with a nice, simple smile the next time it happens. If he stops to talk then you could ask him to see a movie or something. If he only says hi back, then work your way up with small talk. I am one that wants the guy to ask me but most guys are terrified of asking. At least say hi to let him know you are interested. If he likes you it will give him a little confidence to ask you out on a date or to hang out.