I used to have really bad social anxiety. I would feel physically sick before going out, even if I was going to a place i knew, accompanied by trusted friends! If somebody spoke to me my throat would close up, I'd blush and stutter. If I did somehow manage to get into a conversation I'd be so awkward and nervous that people would just look at me with pity.
Exactly like @Misscoffeecrazy3 I just practiced, and forced myself to talk to people, and over time it became less scary and harrowing. When you are friendly, smiley and interested in people then people react better towards you, that in turn brings you confidence. It's like a constant feedback loop, so the better people react, the more comfortable you can be.
There's a book called The Charisma Myth that helped me, also How to Win Friends and Influence People. It's a bit old fashioned now, but basically be kind and interested in people, ask them questions about themselves, use their names in conversation.
It took years, but now i am OK with meeting new people, or being in places where I don't know anybody. People react well towards me, and it feels like a real, genuine connection, not fake or contrived. Some people 'just know' social skills and pick them up instantly. Others (like us!) need to learn and practice.
You can do this! 