Make life easy and reload the OS. Unless you can find some way of bypassing win 10 security and change the password to another one. Google it - U might get lucky!
i suggest getting a flash drive for a quick transfer of files to that so you can clear up space or getting an external hard drive to use as mass storage theres also using an online backup such as onedrive dropbox etc
Connecting a Bluetooth Gamepad
(MENU/123) MENU System Device Manager Bluetooth Gamepad Settings
You can play the games downloaded and installed using the Smart Hub service with a Bluetooth gamepad. Select Bluetooth Gamepad Settings, and then place your Bluetooth gamepad close to your TV. The TV scans for available Bluetooth gamepads automatically. (DualShock®4, a gamepad optimized for PlayStation, is recommended.) After scanning, you can use the Bluetooth gamepad to play games.
This function is not available on certain models in specific geographical areas.
If the TV fails to find your Bluetooth gamepad, place it closer to the TV, and then select Refresh. For more information on pairing, refer to the Bluetooth gamepad's operating manual.