You've got to get out there, a lot. I moved here four months ago, so I was in hyper over drive trying to meet people. There were many days I just wanted to go home and relax, but I'd go to the coffee shops, bars, a John Kerry meeting, or whatever. I'm glad I did, as I've now met a lot of people, and can call a decent number of them friends. I've been very actively looking for groups and such to join: Habitat For Humanity (for some reason this is a great place to meet young, attractive women), Humane Society, political stuff, playing pool at bars, soccer organization, yoga classes, online stuff, coworkers, neighbors, church, you name it I've pretty much tried it, and have had good success. I can even lay claim to an exgirlfriend here. Er, I guess that's not so great
The kid certainly complicate things, but maybe you can find other parents your age? You've instantly got something strong in common.