iPad won't turn on at all

If the force restart does nothing, plug it into a computer. If Finder (Mac) or the Apple Devices / iTunes app (Windows) sees it, put it in recovery mode and choose Update, that keeps your data. A screen that's black but shows up on the computer is a software problem, not dead hardware. Also test the cable and plug on your phone first. A dead cable looks exactly like a dead iPad.

Charge it for a good 30 minutes first with a wall charger, not a laptop port, and try a different cable if you have one. A fully drained battery can show nothing at all for a while. Then force restart. No home button: press volume up, press volume down, then hold the top button until the Apple logo appears. With a home button: hold home and top together until the logo shows. Keep holding past the point it feels like nothing is happening. If it vibrates or makes a sound but the screen stays black, the iPad is alive and it's the display.