I migrated all of my info from a back up hard drive. After it was done t asked me for a password and I entered the previous password I had from my original MacBook but it didn't accept it. What password should I use?

Bohicans wrote:

I migrated all of my info from a back up hard drive. After it was done t asked me for a password and I entered the previous password I had from my original MacBook but it didn't accept it. What password should I use?

Reset your Mac login password - Apple Support

https://support.apple.com/guide/mac-help/reset-your-mac-login-password-mh35902/mac

Change or reset the password of a macOS user account ...

https://support.apple.com/en-us/HT202860