Our family of 5 (ages 15, 12,10) are looking for some adventures in Maine. We want to go hiking to waterfalls/swimming holes, go on some rope swings if they exist there, maybe hit the beach a day or 2 and eat a lot of lobster. Where can we find these adventures? We will be there 7 days. We will rent something on VRBO and have 2 dogs in tow with us. Where do you recommend us staying? We might stay on the oceanside a couple of days and then go more inland depending on what activities are best for us. Any advice is appreciated.

You'll have to check with VRBO (or AirB&B) about which properties allow dogs and how much extra they charge. Where are you coming from with the dogs? Depending on the month, swimming in Maine can be quite cold. I'd check the water temp before dropping from a rope swing.
For sure stop and see the L.L. Bean store while in the area.

You'll find plenty of adventures for kids those ages in Acadia NP, and the rest of Mount Desert Island. there are waterfalls to hike to, carless carrage roads to bike on, and ocean kayak excursions. Lots of ranger programs, too.

June will probably be too chilly for swimming, but sand beach will let you get you ankles wet. Another plus: leashed dogs are allowed on most trails.

Most popular beaches are the sandy ones south of Portland.
Your quest for waterfalls and rope swings might be better answered in Vermont or NH. I agree with Tomfuller that June is going to be cold for ocean swimming and you better dress warmly if you go on any boat trips. There's a fairly recent post about exploring Vermont and the family's plan to visit the swimming hole in Bristol. If you get a DeLorme Atlas and Gazetteer for Maine, you can find the location of waterfalls. We've been to the one in Bristol. If you google swimming holes in Maine, you can find 11 Swimming Holes To Make Your Summer Epic

Yarmouth ME is on the coast just north of Portland and south of Brunswick. We like exploring the Harpswell area east of Brunswick. You can get a print out of conservation areas where hiking and swimming are allowed. Giant Steps only requires a short visit, it's not as popular as the much larger, longer Marginal Way walk in Ogunquit but more quiet and less like a tourist attraction. The lobster place in Cundy Harbor is great but you'll also find others. You might be able to do a day trip to one of the other swimming hole locations but I'm not that familiar with inland Maine geography.

The charm of lobster shacks in addition to reasonably priced steamed lobster dinners is the view. In June you might get lucky and encounter as we once did, a lobster benefit supper which was outdoors under a canopy to raise money for the local volunteer fire department. Pie cost extra but I gave extra points to the lobster places that have good tasting pie. But lobster is also plentiful in New England and if you are near enough to a large supermarket, you can usually buy lobsters and have them steamed at no additional cost. Then you rush home to eat and you only need melted butter, potato chips and pie. If you want to make your own lobster rolls this way, I figure you can get three rolls from two 1 pound lobsters. You don't need lettuce and, gawd forbid, no chopped celery, just a tiny bit of mayo and New England style split top rolls, preferably toasted/grilled.

NH's White Mountains (Conway area) are about an hour from Portland so hiking and more waterfalls are possible if you stay in the Portland area.

Thanks for the responses!!

Back in the day when we were in love and courting we visited Acadia.(we're still in love) I picked up a post card of a waterfall and we went searching for it asking directions from locals that were out. Saw a mile sign and hiked and hiked until we saw another trail sign saying 4 miles this way. We were young and dumb. Hadn't packed enough water and didn't know about lepto. Thankfully the water wasn't falling much as it was midsummer - dumb and dumber. Luckily we managed to reach a ranger roadl that brought us close to our car.

Maine is beautiful in June, and the advice you've received so far has been great. If you go early in June, you will find that the black flies are still around. They have a nasty bite that leaves one of those itchy/ sore lumps. They always got me behind my ears so I couldn't sleep on my side for days.

As to the cool water, both the ocean and lakes are a bit chilly. That never stopped me from going swimming when south of Portland, but once down East (north of there) it was so cold my ankles ached after about half a minute.

You didn't mention where you are coming from, but there is a ropes course in Kittery, Maine. It's called Take Flight Adventures.

Acadia is your best bet, and even though the water is cold at Sand Beach, there is a lovely lake on the island, (Mt. Desert Island) and the water should be warm enough in June.

If driving up the coast, you could stop in Camden, and your kids could hike up Mt. Battie....about 1hour up, and not too strenuous. Great views of Camden Harbor.

For accommodations, you should get right on it. Years ago, when our kids were small, we stayed on Tunk Lake, in Sullivan, ME in a wonderful log cabin. Nice and peaceful, beautiful lake. The only thing is it is about a 40 minute to Acadia National Park, so if that bothers you, you might be better off looking for a place on Mt. Desert Island.

Love Maine...We stayed at the Asticou Inn on Mt Desert Isl..I think it is in Northwest Harbor. Then took a drive up Rt 1 to
Schoodic Point...a bit too chilly for swimming but lots to do at Arcadia NP

Check out: https://www.doddproperties.com/quarry-house. Seems like it would fit your family and it has a swimming hole (quarry) right in the backyard.

There is so much to see in the Rockland/Camden area.