Hi N.,
I am also a SAHM and joined the Mothers Club here in San Bruno. It has been wonderful. I have the support of a wonderful group of moms and there are lots of playgroups and outings for my 15 month old son to participate in and make friends his age. I highly recommend joining one - you don't need to live in the city the club is in.
Also, in Daly City, Fridays 10:30 - 2pm there is open play called Kinder Gym at Pacelli Gym, 145 Lake Merced Blvd., Daly City. My son loved it! They have all sorts of mats & things for the little ones to climb on, plus balls and ride on toys and slides - even a bounce house - and it's only $4. I think they have it on Wednesdays, too. Another great way to meet local SAHMs.
It is so great to be home with the little one, but it's a lot of work. Just be sure to get out of the house! And also be sure to get some time to yourself in the evenings or weekends when you can. One thing about joining a Mothers Club is the babysitting co-op, since you don't have family nearby. Members trade off babysitting time.
Good luck and enjoy this special time!
T.