My iphone 8 screen is dead and does not work at all

My iPhone 6 screen went dead and does not responf to touch at all so cant open phone.My dat limit is close to full so there is a little lock icon at the top.

I have tried to restart my phone by pressing various buttons as described, but after the sequence it always directs me to press the home button and then enter my pass key, but the screeen is dead,

When I plug the phone into the computer the same thing happens, cant work the screen.

Tagati...and thanks.