Are you the trained and experienced Adult Lead on this outing? If so, you already know what you need.
If you are a Scout with advanced training, such as from the Mountaineers MAC program, here is a basic list of what you will need:
Helmet
Harness
Climbing shoes
Chalk bag
Dynamic climbing rope
Rope Bag
60m+
9x quick draws
Belay Device - Cam-assisted preferred
Petzl Grigri or Edelrid Pinch preferred
3x extra locking carabiners
Personal anchor
Petzl Connect Adjust Lanyard preferred
Dyneema Anchor Chain (NOT Sewn Daisy Chain!)
4x slings to build anchors
120cm Dyneema sling to build a quad anchor
Belay glasses
If rappelling - ATC Guide
A dedicated Crag Bag will help you keep your gear organized, stored and clean.