Regarding Internet to use on Carnival ships, there is wifi all around the ship Carnival Wifi. You just connect to it, it is not password protected, then you have to open you browser and you will be redirected to log in screen. Basically screen will take you from there, prices are different and they depend on the length of the cruise.
• Short Cruises (less than 6 days)
o 30 minutes for $16.50 ($0.55 per minute)
o 60 minutes for $24.00 ($0.40 per minute
• Long Cruises (6 days and longer)
o 100 minutes for $55.00 ($0.55 per minute)
o 250 minutes for $100.00 ($0.40 per minute)
If you are going to sign up for internet access, get it on the first day. Carnival runs an internet special on the first day where you can get a few extra minutes added to the package you buy for free.