When i parked at Southampton i drove to terminal and they parked the car for me after inspection for any damage, You litrally stop outside cruis terminal and on return you get a trolly and car park is opposite terminal you just show docket and they will tell you where you are parked, enjoy.
Depends on the berth. Usually you drive up to a luggage drop, leave your cases there for delivery to your cabin. Then park the car and walk a short distanceto the reception hall. Other arrangements e.g. P & O you leave your car and someone drives it to the park while you. just go through reception. There are always ataff there to direct you. Don't worry.