I tried voice over and it has completely shut down my iPad 6generation. How do I get the iPad working again?

If your iPad won't accept your passcode you will need to follow the directions in this link --> If you forgot the passcode on your iPad, or your iPad is disabled - Apple Support

What does completely shut down your iPad mean? Is your iPad able to do anything?

If you need to shut Voice Over off, the following are ways to do so:

To turn VoiceOver on or off, use any of the following methods: Go to Settings > Accessibility > VoiceOver, then turn the setting on or off. Summon Siri and say “Turn on VoiceOver” or “Turn off VoiceOver.”. Triple-click the side button (on an iPhone or iPad with Face ID).