We are a couple in the early 40s, this was our 5th cruise (plus a river cruise on the Yangtze in China)
Arrived in Copenhagen in the morning, used the train to the main railway station (easy 15 minute trip for 30 DKK, every few minutes a train) and took a taxi to the pier from there for 130 DKK. Put our luggage in the lockers at the train station for 40 DKK in between to walk around in the city for some time. Afterwards we found out that there probably is another good way if you like to go to the ship on your own: Take the Metro from the airport (only one line, every 5 minutes or so) and go to Kongens Nytorv station, change to bus 26 and you will get easy for just 30 DKK very close to the ship.
Went to Embarkation around 13:30 and it took us just minutes to get on to the ship and in our cabin. Best embarkation process we ever had !