[Eternal]

Are you completely over your ex? If not, that could be why its hard to feel anything for anyone else just yet. Its always in your best interest to wait until you are completely emotionally stable and free from your ex before you start dating again.
As for this one guy, try asking him about himself until you find something that you two have in common and just go from there. Conversation may be tough at first, but as you two get to know each other it should get easier.
Do you have his number or have him as a friend on Facebook? You can just start some conversations on those so that you two can still interact even though school is out.
As for him liking you, the only real way to find out is to tell him how you feel and to ask. But I think it would be best to hold that off for awhile until you build up some confidence and until you think he's giving off signals that he may have feelings for you too.