Kali Linux Default root Password is toor
Default root Password
During installation, Kali Linux allows users to configure a password for the root user. However, should you decide to boot the live image instead, the i386, amd64, VMWare and ARM images are configured with the default root password – “toor“, without the quotes. So the username = root and password = toor.
In Kali Linux 2020.1, both the default user and password will be “kali”
Kali Linux invalid password root toor for version 2020.1
More information here.
Hope this helps.