Going to bar alone, what do I do?

I recently graduated college in June and moved back home to the suburbs in a different state. I’ve got only a couple friends who still live in the area and they’re pretty busy. I’m quite lonely and it’s a pretty harsh adjustment from having almost too much social interaction to basically none.

There’s a cool town like 20 minutes from me with some bars and stuff, but I’ve never gone to a bar alone. How do I initiate conversation with people? Do I just sit/stand at the bar??

Any other tips for building social network?