why can't I delete apps from my iphone 11? I am only removing from home screen, not removing from phone.

Read again -> Related Article -> Delete apps on your iPhone, iPad, and iPod touch

-> Keep in mind that some built-in Apple apps can't be deleted from your device, so you might not see the option to delete an app. Here’s a list of built-in Apple apps you can delete from your device. If you can't delete an app that's not made by Apple, disable parental controls, then try deleting the app again.

I am only removing them from my home screen, not removing from phone.

Yes, -> With iOS 14, instead of deleting apps, you can remove apps from your Home Screen, so that they appear only in your App Library. Learn more about using the App Library.

See also -> Hide purchases from the App Store

Hide purchases from the App Store – Apple Support (UK)

i did an upgrade and i guess my pc had a demo mode upgrade or somthimg

That seems impossible.

A Demo iPhone is a Property of Apple.

This iPhone cannot be used and is not for sale.

Return it to a nearby Apple Store or an Apple Authorized Reseller in your region 

Demo iPhones are sold on the black market, obtained when breaking into an Apple Store or an Apple Authorized Reseller.

If you have bought it from some one, ask you money back.

i did a update on my iphone 11 now i cant delete apps or download apps it says demo mode

how do u remove demo mode from iphone

Do you have a Demo iPhone?

Apple doesn't sell demo iPhones.

i did an upgrade and i guess my pc had a demo mode upgrade or somthimg....now myn iphone 11 is stuck in demo mode i tried reseting it no results

This doesn’t work!!!