There are many amazing ways to have fun at the laundromat, including:
Press all the "coin return" buttons on the machines or check the change receptacles just in case someone forgot or didn't want their change. Maybe you can find enough to afford a soda from one of the vending machines!
Use the lint to make balls that can be crafted into action figures or dolls. That will keep you entertained for a few minutes.
Watch the opening scene on the standup arcade machine over and over again. Move the joysticks around like you are actually playing BurgerTime, Tag Team Wrestling, Zaxxon or whatever 30-year-old piece of crap is there collecting dust.
Take one of the little buggies that are supposed to wheel around your load of laundry and sit in it or climb onto it in such a way that you can still reach the ground to propel yourself, and then wheel yourself around the whole laundromat.
Collect the old dryer sheets laying about the folding tables and try to make origami animals out of them, give up after you remember you don’t know how to make origami animals.
Try to figure out why the dingy walls somehow smell like recently dried paint.
Watch the bolted to the wall television that is presently stuck on Judge Judy.
Stick your head inside one of the washers or dryers and yell "Echo!" or any other phrase so long as it maximizes the acoustics and your voice reverberates well against the metal interior. Ask other patrons around you if they can hear you.
Go into the bathroom and wonder when they are going to replace the sink that was obviously pulled from the wall years ago.
Ask your mom when you can go home again and again.