How do you make friends as an adult?

I am 31 years old and I don't know how to make friends. It is hard for me to admit that.

Growing up I had friends in school and then friends in youth group when I was homeschooled. I now live 7 hours from where I grew up so I only "see" those people on Facebook.

I went to a small college where I transferred in and then graduated earlier than most people. I had a few close friends but again, I live atleast 2.5 hours from those people.

I have what I consider a close friend at work. She is awesome but I cannot hang out while working. And my work schedule is one week "on" and I cannot leave the building for that week.

On our "off" weeks, I come home and I am 1.5 hours away. So we never wind up hanging out.

I don't have children and I live in a very rural neighborhood. I am also fairly shy which I know sometimes comes off as "stuck up" if you don't know me.

I have started to get involved in children's church. There are great people at my church and it is small enough to make friends. And yet it seems everyone my age has children. Honestly though, I find it hard to try. Do you go up to someone and ask if they want to hang out? That sounds weird coming from someone you only see every other week at most.

The internet has helpful hints to join a gym or have a hobby. Maybe it is time to do something. How do you make friends as an adult?