We're on the South Shore! Seconding everything Jess recommended-- she's pretty much the expert on all things AP/NFL in our area
Additionally, there's a group called South Shore Mamas that has a Facebook page and its own blog. It lists a lot of fun free activities.
The South Shore Natural Science Center in Norwell (www.ssnsc.org
) is another great thing to do, although 2 might be a bit young. They have family-friendly movies on Friday nights, last week was Finding Nemo, and you might find some families there.
Finally, I recommend hitting the public playgrounds. Gaffield Park in Norwell Center, the Birch Street Park and Hobomock Elementary in Pembroke, the Duxbury Free Library and Alden School in Duxbury, and Stephen's Field in Plymouth (which is where the Farmers' Market is located) are all good locations that attract a lot of families and make it easy to strike up a conversation.
We go to every farmers market, usually at the beginning so we can get things that run out fast.