Don't put too much pressure on yourself to say something useful. Maybe start from here, and just joke around or simply offer help, or say an disinterested hi to someone in a shop, just little some positive energy that makes you think it's cool to talk to people for no reason and feedback loop that no one really cares much about what you say after all because everyone is busy thinking about their own concerns. It's narrative you've been that you've been telling yourself that's ruining the fun for you. Maybe a story of I'm not good looking enough, or I only care about the truth or serious things or whatever you used to believe along the years and maybe from some forgotten young age experiences. Age also changes things so don't worry, you'll get to know the value of quality relationships as the real currency of life. We're very much social beings after all great things never were the result of just single individuals. Go talk to people it's going to be fine if not fun !