In your church’s main fellowship hall or gymnasium. Have all the young people bring dome tents (the kind that stand without having to be staked into the ground, most new tents are of this sort). They’ll also need all their camping things like sleeping bags, pillows etc. Set it all up in the gym, with a fake campfire in the center, those fake fire logs that plug in, or red cellophane placed amongst a stack of firewood, with a light bulb under it shining through the cellophane.
Have all the usual camping type fun, in a simulated way, we got all the campers to bring flashlights and turned out all the lights and got them to use their flashlights to see if they could find all the little plastic insects that we had scattered around the gym. Having songs and devotionals around the campfire. We cooked on barbecues just outside the doors. We did pearl diving using a kids swimming pool and marbles, that they had to see how many they could grab with their toes.