Since you are flying from Orlando (big airport with lots of flight options to Amsterdam) you are likely fine arriving day of your cruise. But as others have said you might be glad to have a day or 2 to rejuvenate and see more sites. That’s up to you. We much prefer staying outside Amsterdam (Haarlem, Delft and Leiden are all beautiful historic towns out of the bustling, dirty Amsterdam). Trains in the Netherlands are frequent, inexpensive, clean and easy to use. You can be at Amsterdam Centraal in 30 minutes or less from any of those towns.
while you can easily take a train from the airport to Centraal I’d probably be inclined to do a cab or an Uber or a car service from the airport because I’m not wild about hauling my luggage onto and off a train, across a 6 or 8 lane highway to the river outside the station (while dodging hundreds of homicidal cyclists) and then a few more blocks to the ship. If you are flying in the day you board your cruise the simplest way to get there is just use Viking transfers. Not the cheapest, but certainly easy. They will be standing there with a sign as you exit the customs area into the arrivals hall and they’ll take your luggage and escort you to the van or bus and deliver you to the ship.
if you fly in a day or 2 early, unless you get a thrill from dragging your luggage around get an Uber. 😂