Also what safety equipment would an adult need to ride a quad??

A helmet and an orange flag. I believe that is all. Feel free to give them a call during their business hours, they're good people.

Orange flag... sold on site and helmet

I was just a passenger in a Jeep the day I was there. Pretty sure helmets were required for quads and ad mentioned, orange flags are required. Our group brought their own but you can buy them at the Cliffs as well.

Helmet and orange flag