I worked for Princess at one hotel and at the Whittier Port.
You will get a Welcome package when you check into your hotel that will have luggage tags for your trip.
One bag for your land portion and one bag for the cruise. You will put the tags on your cruise bag with your name.
The next day you will put your bags outside your room that night. They will be picked up by Princess and taken to the correct lodge and correct ship.
You will have a small carry on for your trip on the coach or train (depending on what transportation you choose).
DO NOT put meds, money, travel docs or anything personal in your bags going to the ship or lodge