I had to order my son's meal in restaurants until he was about fourteen. He couldn't talk to the server himself. He had very few friends. He could talk to his family, but had great difficulty talking to others. He would whisper his food order in my ear to tell to the server. That changed for him. He modelled me. I also have some social anxiety, but I counter act it by being the first one to talk to whomever I encountered. I would walk up to a counter and say "Hi, how are you?" You see, now you've put them on the spot, now it's about them doing all the thinking, they have to formulate a response. Meanwhile you can think about what you want to say next. If you have difficulty talking to others, then try and start the conversation, before someone asks "how was your day?", ask them how their day was. So now they have to do the talking. If it bothers them that you give one word answers, then rotate the words, fine, uneventful, okay, good. "How was your day" is actually just a question that requires you to acknowledge their existence. It's a protocol people use. I actually don't like that question, because to truly answer it would require several paragraphs, and I'm not convinced the party asking the question actually wants to hear several paragraphs. Or you could think up a sentence to say, like: okay I guess, how was yours? Then let them talk.