undecided, Welcome Aboard as well!
Great advice from Cruise Specialist and TrvlPro. To throw in my 1 cent, usually I reccomend a shorter cruise for first timers, but in your long awaited case I would go with the 7 day Conquest as Neil suggested.
Your cabin type is a personal preference, I don't spend much time in the cabin so I opt for outside or inside and save the money vs a balcony. Other people swear by the balconies.
You can call Carnival directly if you choose, but as Cruise Specialist said it does not cost any more to get your own Agent.
Here is a link for Carnival Agents, just put in your zip code and talk with a few
Like Neil said you are overdue. You will have the time of your life! The only bad thing about cruising they don't put in the disclaimers is:
Cruising can be addictive. Consult your local Travel Agent should you experience symptoms.
Best wishes, and it will be awesome no matter which you decide.