The screen is a critical component of the iPad, so it can cause a lot of panic when it suddenly has issues. Aside from the button or two on the sides of the iPad (and a Home button on older models), ...
Press and hold a volume button and the top button, or just the top button if the iPad has a Home button. Next, slide the ...
If your iPad screen won't rotate, you might have to turn off the Orientation Lock or do some other troubleshooting.