When you configured the Workspace ONE Access virtual appliance initially, you created passwords for the admin user, root user, and sshuser. You can change these passwords from the appliance configuration settings in the Workspace ONE Access administration console.
You can also change the admin user password from the command line. See Resetting Admin User Password for Workspace ONE Access.
Make sure that you create strong passwords. Strong passwords should be at least eight characters long and include uppercase and lowercase characters and at least one digit or special character.