Take a look at wolfes neck farm in Freeport. They have camp grounds overlooking the ocean and playgrounds and farm animals for kids. They have a bunch of options ranging from tents to RVs to cabins.

https://www.wolfesneck.org/visit/camping

Look at Mt Blue state park in weld Maine. It’s got a beach, playground, hiking trails. We have gone a bunch of times with family and the kids all love it!

Everyone in Maine just camps in the left lane.

We love Mt. Blue. Crystal clear lake, sand beach, ranger cabin with various programs, including panning for gold in the Swift River. Yup. Good calm, friendly family vibe.

Depends if you want resort camping or back country?

I recommend Vermont or New Hampshire

The Maine State Park system has great options for car camping and family camping. You can expect a gravel pad, fire pit and a picnic table at each site and an easy walking distance to water and out-house. Many feature excellent lake access and short hiking trails. Sebago and Lily Bay fill up very quickly so check out the website to see when reservations open.

This is the answer.

When are you planning on camping?

Late August or Labor Day

Resort as there will be several little kids.