This being the OB, I should remind you that you CAN NOT take weapons onto USAFA, so lock them in your hotel room. Sometimes the guard people want your car registration and insurance, too. Once you are on the grounds, you have a surprising amount of freedom to snoop around. The exception is the actual cadet area: the dorms, classrooms and mess hall, which are off limits . But you can look over the Terrazo, their Quad, from the Chapel area. Try to be there at formation, they march to chow. I recommend a guided tour of the chapel to learn as much as possible.
The visitors center there is nice, you can also self tour their sports complex, which has a gym, ice rink, swimming pool and more. Look for the air field viewing area on the south end, which has some airplanes on a stick, and you can watch glider and parachute Ops if your timing is good. The best views are after entering the north gate. There's also a B-52 on display on that road.
In the Royal Gorge area, we enjoyed he train through the gorge. We had tickets for the skyliner car, but spent the trip in the open gondola car. At Canon City, go over Skyline Drive. It is spectacular, and there are dinosaur footprints in the rock along the road.