What to do before my crush walks out my life?

i have a crush on this guy for about a year. i was introduced to him through abouther friend making a joke. i think he likes me to by the way he stares and looks at me. after school, he always hangs in a place thats near my locker or where i usually am. i kinda just can feel the weirdness or connection. like when i see him in the lunch room. the thing is that i know but dnt know for sure if he likes me. he is about to graduate from my school for good in about a month :'(. i am shy and dnt have the guts to say anything to him. but i want us to at least speak before he leaves. HELPPPP! I really doubt that i would walk up to him. any otherr signals that i could send?