I am trying to update my iPhone 11, but it doesn’t even allow me to go to update screen

Oh ok. Does restarting your phone allow you go to into that software update panel? The instructions to do so are here: Restart your iPhone - Apple Support

If that didn't work, using a PC or Mac, you can alternatively update your iPhone from there by following Update your iPhone, iPad, or iPod touch with iTunes - Apple Support

Is the “Software Update” button greyed out? Do you get an error message while attempting to visit the update screen?

Settings, General, VPN Device management, is there any control profile installed?

and

Settings, Screen Time, turn it off

Can't do that if its controlled by your school or work ir if you have screen time blocking you.