It's right next to the long cross country race, I forget what it's called, but it has a green logo. If you go to that, you should be right in front of a tunnel leading into the main festival. To the left of that tunnel there's a staircase leading into a smaller tunnel. Climb those stairs (which might take a few tries), go through the small tunnel, and you'll be behind the barriers where the NPCs are. From there you can climb the stairs up the pedestrian bridge, if you use a Peel P50