No one should visit Zion without taking the drive to the end of Zion Canyon. Save at least 3-4 hours minimum. Free shuttle is available during peak season. Seasonal restrictions apply for individual vehicles. See NPS.gov
A short walk / hike is also a must. We recommend the river walk at the bottom end of the “Zion Narrows” hike. The first mile is paved and gentle. Be sure to check the weather forecast, since flash-flood danger is high in this area. Other classic short hikes include Emerald Pools, Weeping Rock, and Canyon Overlook.
Zion National Park is a big place, but most tourists only see a small fraction of it. The best way to see the outback sections in a short time is to take a helicopter flight or back country safari.