Reset phone settings

If you're needing to reset your device, there are a few different options.

First, go to your settings app on your device, scroll down and select "General management" > "Reset" 

Reset settings: This will reset all settings back to their default
Reset network settings: This will reset Wi-Fi, Bluetooth, and other network settings back to their default
Reset accessibility settings: This will reset all accessibility settings such as keyboard shortcuts, voice assistant settings, font size, special screen settings, etc.
Factory data reset: This will reset your phone to factory default settings. This will erase all data, including photos, contacts, and any other files. 
Auto restart: This will automatically reset your device 1 hour from when you toggle this option "on"