My wife and I went to pictured rocks some years back and it was beautiful. We did an evening boat tour and it was a great experience. If there are openings I'd recommend a sunset tour, but any time is still great. Munising is a cute little town and we hung out just checking out various shops while we were there.

There are some waterfalls near munising and you'll see them on your way in. If you have the time, Tahquamenon falls are probably the most prominent ones in the UP. But they are going to be very out of your way. Unfortunately, everything up there is VERY far apart, so be ready for the long drive.

I grew up in Michigan and spend a majority of my summers camping in the UP. Marquette is a neat town if you want a city nearby for lunch or dinner. I'd recommend doing one of the glass bottom shipwreck tours, I believe there are a few different ones. I did one that took us out to see the shipwrecks, and also went by the pictured rocks, so I think it was likely out of Munising. If you stop in at any touristy area, there will be tons of pamphlets for local things to do, which are great for people in your situation.