Have you made sure you have connected all of the required ones, like the battery, screen, earpiece and digitizer? Make sure they are pressed all the way down gently if you need to. This is what happened with my iPhone XR.
To get out of recovery mode, make sure your USB cable is connected to both the laptop running iTunes and your device.You may need to hold the home button while connecting your USB cable as above. Now hold the home and sleep/wake buttons together until you see the Apple logo appear.