Go to the NCAR parking lot and explore the system of trails behind it. There are miles of them ranging from relatively easy hikes at the base of the Flat Irons to the strenuous 9 mile loop up to the top of Bear Peak and back down. I walked up the canyon and ridge to the peak, then down Fern trail but if I did it again I would go up via Fern and back down the ridge and canyon. Depending on your fitness level and desire for challenge it may be a little more than your looking for, but the view and scenery are worth it.
There are tons of places to eat, but since I am a tourist there as well I will let some locals chime in for that.