Hello piller99,
Thank you for reaching out in Apple Support Communities. If you haven't tried yet, we recommend for you to restart your iPhone. This is a step that can help resolve unexpected behavior. Once your iPhone has been restarted, please check and see if you can set up your Gmail account. If needed, here's how to properly restart an iPhone:
How to restart your iPhone X, 11, 12, 13, or later
1. Press and hold either volume button and the side button until the power-off slider appears.
2. Drag the slider, then wait 30 seconds for your device to turn off. If your device is frozen or unresponsive, force restart your device.
3. To turn your device back on, press and hold the side button (on the right side of your iPhone) until you see the Apple logo.
Following these steps may help and is outlined in this article: Restart your iPhone - Apple Support
Kind regards.