None of the answers I see writes about the main currency of social people: looks. Go to the gym and get to the top 50 percentile of people there (be able to do 15 pull ups, 40 push ups). When you get older this will get much harder, so use your youth to maximize your genetic potential. It will be boring, but most people do boring stuff all their lives.

There are of course other aspects of looks as well, try to get into the top 50% in all of them, and then try socalizing.