If you connect your android device with your computer by USB cable and your computer does not recognize or show your android.
These following steps and try to connect your device.
Make sure your android is unlocked.
Check that you have the latest version on your android device.
Make sure your device is turned on.
If your device locked in trust mode, then unlock it quickly.
Unplug all USB accessories from your computer except for devices.
Try every USB port to see if his works.
Restart your android and PC.