We stayed there last July, and were quite happy with all the facilities in the park. Nice wooded camp sites, very roomy, many had a lot of privacy except in the center section. I believe the tent section was the one nearest the waterfront. Very nice staff. Firewood available. No wifi but you can drive to the public library and get it sitting outside.
There's a nice small restaurant by the park's golf course where we had drinks one day. Herring Cove is close to the Roosevelt summer home. We enjoyed "tea with Eleanor" offered twice a day, free tickets.
Worth driving to the lighthouse. You can take a ferry from Campobello to Deer Island and see one if the world's biggest tidal whirlpools, the Old Sow. There's a campground overlooking the whirlpool by the lighthouse. Free ferry from Deer Island to the New Brunswick mainland.