@ninjacolin is onto something.
Practice with strangers that you’ll never see again. Talk to people casually in a grocery store (cashiers are good, because they’re a captive audience and will smile at you as you say the stupidest things imaginable). Just start chatting about the weather with people at a bus stop.
It hardly matters what you say, as long as you get into the habit of ‘talking to people you don’t know.’ Then when you meet someone you’d really like to talk to, it’s just “more of the same.”
It ain’ no thang.