Glacier Nat'l Park is stunningly beautiful and it has trails graded from wheelchair accessible up to deep backcountry treks. You should be able to find a few trails there you feel comfortable with.

Glacier NP does attract quite a few visitors, so finding camping can be tricky. My wife and I had good luck staying at a Forest Service campground on the Blackfoot River, near the western entrance - then driving into the park each day to hike.