By default root does not have a password and the root account is locked until you give it a password. When you installed Ubuntu you were asked to create a user with a password. If you gave this user a password as requested then this is the password you need.
What is the password for root?
The root password interface provides the ability to maintain system security by changing the default password for the root user of the Unitrends system. The default password is “unitrends1”. It is highly recommended that you change this password from the default.
Does root have a password on Linux?
Conclusion. By default, in Ubuntu, the root account has no password set. The recommended approach is to use the sudo command to run commands with root-level privileges. To be able to log in as root directly, you’ll need to set the root password.
What is Linux default password?
To answer the literal question: no, there is no default password. Usually by default an account will have an “invalid” password, that is, a password hash that will not be matched by any password at all.