iPad not coming on

Connect to your Power Adapter (charger) - and allow the iPad to charge for at least an hour. After one hour has passed, whilst still connected, attempt to turn-on your iPad.

If nothing happens, whilst still connected, attempt a forced-restart:

• On an iPad with a Home button: Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.
• On an iPad with Face ID: Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the top button. When the Apple logo appears, release the button.

If your iPad still doesn’t turn on, or if it gets stuck during start up, see the Apple Support article If your iPhone, iPad, or iPod touch won’t turn on or is frozen.

Try to force your ipad to reboot. Hold down the sleep and home buttons for about 20 seconds or so. If you see the silver apple, let go and let it reboot and see if that helps

If your ipad does not have a home button there are instructions at the link

Restart your iPad - Apple Support

Beyond this, is the battery charged? Could it be out of power? If you think so, plug it in and let it set for at least half an hour and see if there are any signs of life