You've successfully snuck around to the back of the carnival area without being spotted by anyone in the huge line at the front or any of the carnival workers in the nearby trailers. You've yet to find a way in to where the public are, but you can hear them on the other side of the wall in front of you.
There happens to be an oval shaped hole in the wall, big enough to poke your face through, where you could could see what's happening on the public side.
To your right, a wooden stairwell leads to a small door. If you went through there, you might be able to see everything from above the crowd's eye level.
To your left, there's a small door that is probably the back entrance to the fun house.