Hi DeborahB#12,
Thank you for posting in Microsoft Community.
Just to clarify, are you able to sign-in using your password? If yes, you may try removing the PIN, restart then set it up again using a different number. Open Start > Settings > Accounts > Sign in options > remove PIN Enter your password > Restart when you complete > Go through the steps to set it up again.
If you're unable to sign-in using Password or PIN, we suggest to reset your Surface device.
- From the sign-in screen, press and hold the shift key on the keyboard, select the power icon in the lower-right corner of the screen, and then select Restart. Keep holding the shift key until the device restarts and the Choose an optio n screen appears on a blue background.
- Once Windows Recovery loads, release the shift button, and then select Troubleshoot> Advanced options> Reset this PC> Keep my files.
- After your device has restarted, try signing in with your PIN again.
Also, makes sure that you have the latest updates installed on your Surface Go. You can check for the latest updates by selecting the Start button > Settings > Update & Security > Windows Update.
Let us know if this help with your concern,
Loyd G.