You should choose one or two active recreational activities and do them routinely. For example, soccer, rock climbing, golf, martial activities, running, biking, gym, whatever. You are more likely to meet friends through those activities who also enjoy doing the same non-alcohol activities as you.

Dating and sex also don't have to involve alcohol and are fun activities as well.

Better to get on these things now while you're 23, rather than 33 or 43.