I’ve moved around a lot since college, and have had to build a social network from scratch a few times with varying degrees of success.
While the advice to join a social activity centered around a shared interest is solid, it’s not sufficient by itself for making friends. Bridging the gap between hanging out for a given activity to hanging out more generally to being actual friends with someone is hard.
Make one friend that is just down to show up. With at least one friend that you can consistently count on to show up, you can start inviting other potential friends to things and build out your social circle. You have to be open to rejection and to a bit of awkwardness that comes with two semi strangers hanging out. But with one anchor friend it becomes so much easier to make more and it’s the one piece of advice I wish I’d come across sooner.