While on a standard field trip with your class to the dinosaur museum, your teacher warned everyone to stay with their buddy.  After some time in the museum, you needed to go to the restroom. Your buddy was engrossed in a nearby exhibit. 

"I'm going to find the bathroom. I'll be right back," you said to your buddy.

Without looking up from the plaque, your buddy waved their hand and replied, "Okay, I'll be here when you get back."

You wandered off to the restroom. After washing your hands, you went to leave only to discover the lights in the museum were off, but the exhibit lights were still on. You used those lights to navigate your way back to the spot where your buddy said they'd be. But your buddy, your class, and other museum patrons were gone. And it was eerily quiet in the museum.

You'd never been alone in such a big building before, and especially not alone without any big lights. You made your way back to the front doors and saw they were locked with a chain. You pushed on the door and chain but they were indeed shut tight.  A note lay on the floor as if someone had slid it under the door. 

"Find the clues around the museum to unlock the doors. Good luck."