iphone stuck on the apple logo and will not restart

Force restart iPhone - Apple Support ⬅︎ TRY THIS, and if it does not work try Recovery Mode...

Force restart an iPhone with Face ID, iPhone SE (2nd generation), iPhone 8, or iPhone 8 Plus

1. Press and quickly release the volume up button.
2. Press and quickly release the volume down button.
3. Press and hold the side button.
4. When the Apple logo appears, release the button.

Note: If iPhone 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.

Recovery Mode... the full info is in the above link...⬆︎ the short info is below...⬇︎

Connect your device to a computer. On a Mac with macOS Catalina 10.15, open Finder. On a Mac with macOS Mojave 10.14 or earlier, or on a PC, open iTunes.

Press and hold both the Home and the Top (or Side) buttons at the same time. Keep holding them until you see the recovery mode screen.

Well the best thing to do right now is contact Apple for further help, you can click "Contact Support" top right corner of this page and follow the leads until you reach the Phone or Chat options.

They are very busy right now so it might take a few tries to reach them, also not all options are always immediately available.

You may also try here...Contact Apple for support and service - Apple Support

my Iphone 8 plus was shut down and when it come back on the apple logo stays on and will not go away. and some times it will shut its self down then come on to the white screen with just the apple logo. nothing else happens. i have let the phone die and charge it to allow it to come on and have done the up down volume button then side button to shut it down again but it continues to do the same white screen with apple logo

Corrected info...

Press and quickly release the Volume Up button. Press and quickly release the Volume Down button. Then, press and hold the Side button until you see the recovery mode screen.

That line replaces...Press and hold both the Home and the Top (or Side) buttons at the same time. Keep holding them until you see the recovery mode screen.