what is the MAC password, i just replaced my old mac and the new one is asking for the MAC password, I have no idea

+1 if you migrated the old Mac to the new Mac then first try the old Macs password. If you did not migrate, please use the information in If you forgot your Mac login password

During setup? Most of the times it is asking for your old Macs password (if you haven't deleted that one from your account yet)

Haven't you set up a password for your new Mac? If so, try that one