How can I talk to my crush?

Ive seen him at school a couple of times but I dont anythinh about him besides his name. But this next semester I know some of my classes are changing so I will only see him on wednesdays after 3rd pd going down the hall to my next class...but its walking down the hall the opposite way for like 3 seconds and thats it plus there are alot of ppl in between us...so idk what to do? And I really just need a time where I can talk to him and introduce myself...can anyone help me?(: thanks so much.