Hello Beauty3547,
Thank you for posting in the Apple Support Communities. Reviewing the related article If your iPhone won't turn on or is frozen was a great idea, and we'd like to provide some additional clarification.
To force restart your iPhone 11, you won't hold the power button and volume button at the same time. Instead, you'll 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 Apple logo.
If the issue persists, we then recommend following the steps in the section "If your iPhone turns on but gets stuck during start up" from that article above.
We hope this information is useful. Kind regards.