I would suggest starting with trap, sporting clays are a tuff start and you do not have the latitude to move around and make it easier on the shooter. Remember you want the youth to have fun and just bust em his first couple of times out. You have plenty of time to increase the difficulty. Trap is much more flexible for you to adapt an easier shooting solution. Down side is if it is public range you may not be able to move forward. You might talk to the RSO (range safety officer) and explain to him what you want to do and that is first time youth shooter. Then ask him how to proceed, if you can move closer to the trap house for a few warm up shots. Typically the local ranges are so enthusiastic about youth shooting they will make most any reasonable accommodations. Just be up front with them.
