Having done multiple day trips to the canyon from the valley, flag, and pine/strawberry area....
For you, I suggest the Grand Canyon Village at the South Rim of the Grand Canyon.
You can literally park 20 ft from the edge in some spots. It is basically a village along the edge of the Grand Canyon. There are multiple restaurants, a historic hotel, an art gallery, a bar, and views for miles!! That whole area is designed for tourism and is paved paths with benches everywhere and relatively flat! It is all extremely accessible.
Yavapai point and Mather point are further away than the map shows so drive to those. The Desert View watchtower is also about 20 mi east and worth the look. They have a bus service that also take you to the different viewpoints along the rim edge!
I also suggest taking the scenic route through flagstaff on the 180.
Sunsets are spectacular usually. And we eat at the Bright Angel lodge more often than not, the food is decent. There is the Arizona Room, and El Tovar Dining room(finer dining)