Do you mean by car, bus or train?
The instructions sent by your cruise line shortly before departure will tell you. It is really very easy--quite the simplest start to a holiday! Basically, arrive,give baggage(except hand baggage) to a porter, go to check in desk, complete staight forward procedure , go to departure lounge, via security screening and wait til you are called for boarding. You will be told what to do and when to do it. Its all quite simple and pleasant and MUCH better than airports!!