Enjoy some beautiful short hikes in the area (Ex: Virgin Creek Falls) or take the gondola lift to the top of the mountain, you won't be disappointed either way. The resort has a lovely Nordic Spa (It's worth it!). I also highly recommend eating at Jack Sprat and enjoying a beer at Girdwood Brewery Company.
Great for families!
If you want to see more of Portage Glacier (vs. just a drive-up viewpoint) I would recommend doing the Portage Pass Trail: This is a moderate, 4-mile roundtrip hike with stunning views of the glacier, lake, and Prince William Sound. If this interests you, then you will need to take the tunnel into Whittier.
There are plenty of fishing charter options out there! Here is just a quick link to a few of them.
If you plan on turning this into a full vacation and need more recommendations please reach out to Audrey. Other beautiful areas to check out include: Seward, Homer and Denali. All of which have incredible hiking and fun things to do.