I'm 25 and I'm at a point where I look good, have a good job (in my opinion), and have plenty of confidence. However, I have zero friends. Over the years, since high school, everyone has moved, or gotten addicted to drugs, or is homeless or in jail and I have cut ties with all of them.
I can't really make friends at work, and I don't go to school. My only real 'extra-curricular' activity is going to the gym to lift.
From my starting point, how should I go about trying to build a social life?