Find your nearest library and find out when the age-appropriate storytime is held and go every single week. You can also check out the storytimes at local bookstores.
and start going to 1 or 2 events a week. My local moms club chapter had events every Tuesday and Thursday, sometimes park days, sometimes craft days, theme potluck parties, field trips to area museums/firestations/policestations/child-friendly-businesses, etc. They also had small playgroups on Wednesdays, at various member homes. Once I settled into my moms club chapter, I found that it was helpful to my psyche to actually volunteer within the group and have regular "jobs" to complete. For a while, I was the newsletter editor and later became the President. Volunteering really helped me feel like I had purpose and deadlines to stick to, and simply helped my psyche.
Attachment Parenting International also has playgroups and if there is one in your area, you should go to it as much as possible.http://www.attachmentparenting.org/groups/groups.php
Depending on your child's personality, I would find the nearest free parenting magazine and I'd check out all the local businesses aimed towards children, and I would start using all of the free visit coupons and offers. Places like Kindermusik, Music Together, Gymboree, My Gym, Mommy & Me classes, gymnastics venues, etc. Get a membership to any children's museums in your area and go once every week or every two weeks.
Take daily walks with your child, with either a carrier or stroller and get fresh air and exercise for both of you.
Hope that helps.
p.s. I found that the more time we spent out of the house, the tidier the house remained.