You are booking pretty far out so you may want to book early saver fare. If the cruise fare drops you can put in a request and get the price difference as on board credit. Which is good because Carnival adds $10 per person per day in tips this OBC can be used towards that. However, Early Saver is non refundable you can change ships and dates for a $50 per person fee. If you use Early Saver with a Travel agent the TA has to put in the early saver request. Be care some Travel agents charge a fee everytime you request the early saver price decrease. This is why I prefer to book myself. I also check the cruise fare regularly and put in my requests right away.
On the room if you want some alone time with your spouse it would be nice to have the kids across the hall. However, if you are concerned your teens will be out all night getting into trouble then sharing a room would be a good idea. I love the 9C rooms because the extended balcony is quite large. With so many people in the room you might consider this that way you can all enjoy the balcony together at the same time. On deck 7 empress deck
the 9C rooms are 7454 and 7459 they are always aft on the corners.
The 7C cove balconies are a fancy way of saying under the life boats. Some people like these room because they are more private noone can look down at you. Other people don't like these rooms because they feel cramped and much lower to the ocean you may get wet. 7C rooms are on deck 2 Main deck
I like being up high. My favorite is deck 8 Verandah deck
there are 9Cs on this deck 8466 and 8473. Verandah deck towards aft is close to the lido deck for the breakfast buffet and swimming pools without the noise. On Dream lido deck is deck 10
. Because there is a deck bewteen you and Lido deck so you won't hear the noise on lido deck while you are trying to sleep. If you chose a 8A-8M to share then I suggest you try to get a balcony room that is AFT the balconies are deeper in the back of the ship. I hope this helped you instead of confusing the heck out of you.