One of our students put on Guided Access, no he can't remember what code he put in. The iPad is locked into that app. How do I restore or do what ever to get my iPad back.

If the iPad has a screen lock passcode set, you can reboot the iPad and get the regular lock screen for you to enter the normal passcode (not the guided access one). When you enter the passcode, it should open at the home screen, and you can then Navigate the Settings to turn off Guided Access and its passcode.

See here: If your iPhone, iPad, or iPod touch won't turn on or is frozen - Apple Support

If you have no screen unlock passcode, you will need to restore the iPad to factory condition using recovery, follow the steps here to remove Guided Access: If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled - Apple Support

Try a forced restart. Hold down on the sleep and home buttons at the same time until you see the Apple logo and then let go of the buttons.

Then take a look at this.

https://www.techuntold.com/disable-guided-access-forgot-passcode-iphone/