This was our first cruise too. We weren't sure what it would be like cruising on a Disney ship. But, oh boy, we were hooked. This cruise is a perfect way to test the waters - so to speak. And unless you end up really hating it, you will feel like it has ended all too soon.
There are a couple of different sizes of Balcony rooms on Dream. The ones that fit 4 or less - categories 5A to 5E, 6A, 6B, and 7A - will do the trick for you. You also have several adults-only areas on the ship - plus
Castaway Cay, Disney's private island, has Serenity Bay reserved just for adults.