We did a DYI before our Princess cruise last summer. We flew into Anchorage and arrived at 7 pm, ate dinner and went to the hotel and crashed.
Day 2 we called an Uber to take us to Avis downtown to pick up our rental car. We spent a full day in Anchorage going thru the shops downtown and taking a trolley tour which we caught outside of the Visitors Center.
Day 3 we drove up to Talkeetna and the views were beautiful. It was a long drive and I don't know what all the hype is about therefore, this would be the one thing we did I would not do again. Others might enjoy this tiny town but us not so much.
Day 4 we got up and left our hotel at 5 am to drive to Seward for our tour with Major Marines which we had to be there around 10 am. I wanted to have time to stop and pull over for photo ops and it was perfect timing, this is the most gorgeous landscape I have ever seen in my life! After the tour was over we drove to Girdwood and stayed at the Alyeska Ski Resort and it was beautiful.
Day 5 we drove into Anchorage and just hung out and had lunch at Moose Tooth Pizza (yum) and turned in our rental car. On our last morning before the cruise we called Uber to take us to the train station and we took the train into Whittier. It was an awesome ride and we were one of the first ones on the ship. I hope my little story has help a bit and enjoy your cruise, we can't wait to go back!!