Failed to start ssh.service: Unit ssh.service not found.

It seems that there is an issue with the SSH service on your system. The error message "Failed to start ssh.service: Unit ssh.service not found" indicates that the SSH service unit file is missing or was not installed properly.

To resolve this issue, you can try reinstalling the SSH service by running the following command in your terminal:

sudo apt-get install openssh-server

This command will install the OpenSSH server package which includes the SSH service. Once the installation is complete, try starting the SSH service again by running the command:

sudo systemctl start ssh

If you still encounter issues with the SSH service, you can check the system logs for more information by running:

sudo journalctl -u ssh

This command will display the logs related to the SSH service and may provide more insight into the issue.