Opening lines
The first step is to break the ice (start the conversation). You can introduce yourself with: "Hello, my name is..." or try a more relaxed approach like "Hi, l'm... You can follow up your greeting with a simple question like "Where do you come from?" or a comment on the weather if you're outside, eg, "It's really cold today isn't it?"
It's a good idea to start with something easy and impersonal to help you build your confidence. The subject of weather is an easy one that everyone in the world is able to talk about!