Most of the balcony categories on Princess have the same room size/layout (except for handicap or minisuites). BC cabins are on either Baja or Aloha deck. On Baja, they are more in the middle of the ship, where on Aloha, they are forward or aft. Either deck is good as you would have cabins above and below you (quieter).
The rooms will have bed, desk, closet, bathroom, table & chair, tv, safe. The balcony will probably have a table & 2 chairs. I believe that these are the totally private balconies, rather than the semi or totally exposed ones on Caribe/Dolphin decks. If you've ever seen a profile of the staggered decks, you'll know what I mean.
Personally, I like the BB category on the Caribe deck because the balconies are almost twice as big. My absolute favorite cabin is one of the BB aft cabins C752 or C753.
The Grand is a great ship. Hope you have lots of fun!