Where to socialize ?

I have no friends and have almost forgotten to have non chalant or casual talks with people. I'm day by day becoming more shy version of myself but also want to escape, but I get overwhelmed by seeing others that they are so casual and connect with others so easily. In my workplace I don't have much people of my age. So I want to socialize, pubs are no for me as I m a teetotaler and non smoker. Im living life like a monk lol, despite being in a vibrant profession, I'm working in tech. Any places where I can find people of my age to socialize considering I'm very shy natured and always in dilemma whether to talk to someone or not.