How do I talk to random people?

Hm, I need help. So I have this social phobia, and I really want to speak to these people I see a couple of times a week in my area. But it's kind of, well, extremely weird just walking up to a stranger outside of school all like "Hey, etcetera etcetera..." I really don't know what to do, I'm like overly shy and paranoid. Some pointers?