My new iPhone X screen has cracked

No.

This is accidental damage.

Repair costs vary depending on whether you have AppleCare+ or not. Depending on how you paid for the phone, there may be coverage available for accidental damage through the card issuer.

iPhone Screen Repair & Replacement - Official Apple Support

Hi

No damage is not covered by warranty.

If you have Apple care they you only pay a small amount.

If you don't have Apple care the it will be just under £250.00 in UK

They replace all the case front & back.

Cheers

Brian 🇬-1F1E7;