does iPhone X support ios 13

Yes:

iOS 13 - https://www.apple.com/ios/ios-13/

iOS 13 is compatible with these devices.

iPhone 11

iPhone 11 Pro

iPhone 11 Pro Max

iPhone XS

iPhone XS Max

iPhone XR

iPhone X

etc.

Update your iPhone, iPad, or iPod touch - https://support.apple.com/HT204204 - When you update you will only be given one update selection which will be the highest available iOS version supported by your device

Yes.

Yes .... you just need to update