Carnival's policy prohibits bringing alcohol on board at the port of embarkation. The exception is one bottle of wine per person that is at least 21 years old.
Alcohol that is purchased at the ports of call may be brought on board, but will be held until the last evening of the cruise.
There are dozens of topic threads regarding this. Just do a search using the Find Tab. It is the consensus of the cruse-chat staff not to allow topics that are for the purpose of breaking the cruise line's policies.
I'll close this thread before it turns into a "How to Sneak Booze on the Ship" Thread.