Acadia is an unusual park. It is split into different sections surrounded by non-park land. There are also a number of Islands you can take ferries to. The Schoodic section north of Bar Harbor is the most impressive and what you usually see in photographs with the very rugged coastline. I didn't find the Bar harbor section of Acadia all that impressive. There are of course all those picturesque small coastal towns to see too.
We stayed at the Bar harbor KOA which was a good spot. They would deliver lobsters to your site.