Yes, you are able to disembark once you are checked in & have your cruise card.
Sometimes the lines are long coming back to the ship.
For luggage I always have 1 carry-on, 1 garment bag & 1 large suitcase.
You can carry on your own luggage if you can manage it.
Also, you really are not limited with hand carried items. Again,if you can carry it you are all set.
Hope you enjoy your cruise