This is a great introduction to singletrack for kids.
This short path is a fun introduction to singletrack; there's nothing very technical here. I recommend riding this loop clockwise; take a left at the Y and descend down the hill. There are a couple of water breaks to help erosion; ride through the middle of those rocks. Once you reach the bottom, there's a short bit of the trail that follows the creek, and then you'll ascend up the switchbacks to the trailhead.
All of this trail is in the woods, so there's plenty of shade from the sun...the flip side is there's a fair amount of poison ivy down by the creek. Stay on the mowed trail and you should be fine.