My iPhone 7 is in Zoom mode.

You can try to navigate on the screen by using using 3 fingers to try and drag across the screen to move it. The last step described is to double-tap with 3 fingers and then drag to try and reduce the zoom. After that, I have nothing else to offer, you would need to either contact Apple Support, or make a Genius Bar appointment at the nearest Apple Store for them to examine the device.

Try triple clicking the home button, and if that does not work, try double-tapping the screen with 3 fingers. One of those should get it out of Zoom mode.