Hello,
I am sorry that you are experiencing this issue.
May I please know if you have the option to reset your PIN from the Sign-in screen itself?
Like the one in the screenshot here-
Select the 'I forgot my PIN' option on the Sign-in screen and follow the prompts to reset it.
(OR)
See if you have the Password Sign-in option.
So that you can switch the sign-in option from 'PIN to Password' and use your Microsoft account password to sign in to your device.
Let me know if you still need more help.