i cannot sign in my mac book proo

Change or reset the password of a macOS user account - Apple Support

I had this problem following an update. Follow the password reset process and you'll find that your password still works. You will have to create a new one and this will grant access. You may find, however, that this is just the start of your problems. Loads of stuff, settings, functions, etc have been changed/deleted and you will have to manually reset them. Good luck