Here are some suggestions I always give to new cruisers:
1. EAT SOMETHING before you get to the ship. This may sound silly considering the reputation cruise ships have for stuffing the passengers, but on embarkation day most ships only have the buffet open for lunch. Depending on when you get to the ship, the buffet lines can be very long. This can be very frustrating. You want to see the ship, or start getting that sun tan, but you are standing in a line and there isn't an open table in sight. Grab a bite before you get to the pier, and you won't have to worry about it. Tour the ship, have a drink at a bar, and wait for the buffet lines to go away. You won't be starving, and most importantly you won't be stressed out.
2. If at all possible, get to the departure port a day early. Flying (or driving) in a day early has many benefits. You have an afternoon and/or evening to relax from the trip. You can make sure your luggage all arrived, and if it didn't this extra day gives the airline time to find it. Most of them can get lost luggage to you within a day. With the realities of flying and security these days, flying in a day early means you don't have to worry about missing the boat if your flight is late. You will also avoid the mob scene at the airport as flight after flight of cruise ship passengers arrives. If you are driving to the port you should also arrive a day early. Believe me, it is worth the price of a hotel room to show up at the pier rested, fed, and ready to have a great cruise.
3. The lifeboat drill: for ships departing from the continental U.S., this drill is usually held around 4 or 4:30 pm. It is required by law. More importantly, taking the drill seriously and paying attention may save your life. Cruise ships are very safe, but you never know what could happen while at sea. Some cruise lines are better at doing the drill than others. It may be uncomfortable, but it won't last forever. If it is hot outside, dress lightly and drink some water before the drill. You may be standing around in the heat wearing a life vest for a while, so plan accordingly.
4. Luggage: you will have to deposit it on the pier (except for small carry-on bags). Be nice to the porters on the pier. They are the last people that will see your luggage before it is loaded on the ship, if you know what I mean . Do not panic if your luggage doesn't arrive at your cabin right away. The crew has thousands of bags to load and it takes a while.
5. If you plan to book your excursions with the cruise line you should do it early because the best ones sell out quick. Carnival allows you to book tours on-line before your cruise starts.
6. And the best advice of all........relax and enjoy yourself! I can't tell you how many cruises I have been on where I observed passengers who refused to leave their stress and worries at the pier entrance. They spent their entire cruise whining and complaining about every little thing that didn't suit them. The bottom line is they wasted their money.