Hi. My best advice would be to do as much research before you go as you can. There are loads of cruise review sites and there are detailed reviews from people who have probably done the same cruise as you. There are drinks price lists on there too, so you can decide if the drinks packages are right for you. I have used Cruise critic but also Lonely Planet, Trip Advisor, Cruise.co.uk and You Tube.
You will not have a lot of time in port so need to know what you want to do when you get there. Check if you are docking or tendering. If you are tendering the organised trips take priority, and there may be long queues to get off, all reduces time available. Never be late, the boat won't wait for you! Check out your cruise trips beforehand and prices.
Check out the drink policy for your company, some (like Thomson) sell you bottles on board and let you take to your cabin, most will take it off you until you leave.
Luggage- take soft cases/holdalls may be difficult to store hard cases.
Dress- Most cruises don't allow tshirts/ shorts sandals into the dining rooms, usually smart casual. It is your chance to dress up and get your high heels out. There will also be one formal night but usually not compulsory.
Toiletries- shops on board are limited - take your favourites with you, don't think you will be able to buy them on board.
I'm sure you will have a great time.
