Have any of you ever been to Glacier National Park? What are some must dos?

I am going there on the 4th of July, and haven’t been since I was two. I am going on the Highway to the Sun if it is open, but I just wanted other opinions. Have you ever been to Yellowstone Park? I hope everyone has. I grew up right by it and it is an amazing place. Of course I Love Lewis and Clark Caverns.