You start reaching out and talking to people. Expect some initial trepidation and the occasional epic failure. Learn from it all. You could also try something

You start reaching out and talking to people. Expect some initial trepidation and the occasional epic failure. Learn from it all. You could also try something like Toastmasters (https://www.toastmasters.org/ https://www.toastmasters.org/) which some folks I know have said helped them quite a bit. It's a skill to develop and practice, like any other, except that humans are awful.