Hey, I like you shoes, where did you buy them? Wow really, that's great, I used to go there but now...(Just look for one small thing and start your conversation)
Start by asking him what he does in his spare time? Let things take their course from there. You can find out a lot about a person from just one question. If he's shy tell him what you like to do in your spare time. Maybe he'll open up. Good luck.
Believe it or not "Hi" or some derivative of it is a good start.
look for common event at church and ask if he is attending. bump into him at church and ask say hi... look for him on FB and message him. just make contact.
Hi, My name is................