As soon as you board the ship, go to your state room. Even if is not ready, the room steward will let you put your luggage in it. If it is ready, then just unpack if you want and go eat. I recommend before you leave the state room. Put your valuables in the safe. The buffet and usually one dining room is open for lunch. We do this all the time. No need to cart you luggage with you when you go to eat. FYI. You can do just the opposite when debarking. Leave your luggage in your state room. Go have breakfast. When you are ready, go get it and get off. Never had any problems and no carting the luggage around the ship.