Ryan,
There probably won't be many members at the Acton Carnival; we are only doing demonstration launches and will only be given a limited time to be on "stage". I wouldn't expect to be able to pick up motors unless you arrange it ahead of time.
Enter NARA Park, Acton, MA in Google Maps, click on Satellite and zoom in. We have launched from the hill just northwest of the pond in a past Winter Carnival or the south edge of the soccer fields in warmer weather. Wherever we set up, the trees are only going to be 200 feet away.
Click on the Directions tab on the right of this page and then on Amesbury. It shows the field and has directions. It even gives an address so you can punch that into a GPS device.
TARC is Team America Rocketry Challenge. Click on the Links tab and then Organizations Related to Rocketry. Their web page will explain it all.
Kenn