I have never camped there, but have visited friends who were camping there on numerous occasions. This is definitely for family fun with all ages of members. If you can, reserve a site near one of the large ponds for easy access to fishing. All you will need is a MA freshwater fishing license and a suitable rod and reel. I have seen rainbow trout caught, so I would assume that the state regularly stocks the ponds. The bike trails are spectacular, and connect to the Cape Cod Rail trail system, which goes on for miles in either direction from the park. The camp sites have water, and available showers, but no electricity hook ups. I have seen everything from very small tents to large buses at these sights, although larger buses are limited to the areas that can accommodate them. Camping fees are modest, but reservations are absolutely necessary, especially for the height of the summer season. Make them well in advance for premium spots.
For those of us who live near here in the winter, those bike trails through the Park make extraordinarily good cross country ski trails!