Travel and RV parks in Massachusetts?
The best way in for you is the Mass. Turnpike (I-90). I don't know just where you are coming from, but the interstates in Connecticut are brutal. The Mass Pike is usually good (one steep hill - east coast standards) until you get near Worcester at rush hour.Exit 11A will put you on I-495 and that will take you to I-95.
Just off I-95 in Foxboro is Normandy Farm Campground. I've never been there, but they have one heck of a reputation (good, that is). There are several in others in that area ranging from state parks to full-service private parks.
One other tip, if you go to Boston, try to use public transportation. It is a beautiful city, but the roads were laid out for walking, not driving.