Embarkation Day, walking up the gangway:
Where to start, I mean you get on board and now-a-days they are huge, lots of corridors, hoards of people, doors, lights, numbers spinning at every glance.
Let's take a few steps back and start from clearing customs shore side.
Right after you will probably be greeted by several of the ships crew sat at a skirted table (normally the dancers or cruise staff/entertainers) asking you to hand in your passport to them. This is protocol on all cruise ships. You will have to hand in your passport at some point on the first day so have them ready. Their where-a-bouts simply depends on where the ship has decided to set up its point of control, either on the pier, if there is room on shore, or on board, where you will be guided directly to them upon entering the main ships entrance. At this point of passport submission you might be given your cabin key of which will be printed your name, dining room table number and time on it. Not your cabin number. This will be separate. Some ships your cabin key will be in your cabin waiting for you, so do not despair if you don't get it here.
You will, upon walking on board, be stopped by a member of ships security and asked to pose into an electronic camera for an individual photo. This will be logged in the ships computers for future reference and security. You're hand luggage will need to be X ray'd as will you. No disrespect here, but if you are used to walking around with a pistol for self defense, leave it in the car or at home. Cruise ships do not accept fire arms.
Now you have retrieved your hand baggage you proceed inside. There should be several members of the senior officers there to greet you and a line of either room stewards or waiters waiting to take your bags off you and lead you to your room or to point you in the right direction.
Fear not, if you have a wheel chair, there will be plenty of help to carry you up the gangway. Though check before purchasing your cruise as some companies do not touch wheel chairs once outside of the ship. Insurance reasons.