You'll now have a button in your hand which you can show people by pressing 'Y'. If you accidentally put it away, just go into your backpack and you can pull it back out.
Now you are able to explore anywhere in the camp which means there are lots of places to explore. For now let's jump down and head over to where Ford Cruller told us we couldn't go earlier, when you get there a message box will appear on the bottom saying "Entering Main Campgrounds."
Right before you enter you'll get a little scene with some kids who are blocking the way. They tell you about arrowheads which you should already have a decent amount of, they only ask for one to get out of the way.