If your phone stays in Recovery Mode, you can first try to see if you can exit this mode, as follows:
- Unplug the device from the USB cable.
- Hold down the Sleep/Wake button (or Side, depending on your model) until the iPhone turns off and then let it go.
- Hold it down again until the Apple logo reappears.
- Let go of the button and the device will start up.
If after doing so, your phone still is not working properly, you will need to make a Genius Bar appointment at your local Apple Store or Apple Authorized Service Provider to have them take a look and provide you with your options.