When you create your service you create the hosting service password. This will be your password to use to log in directly to Direct Admin along with your default FTP and webmail account. If you do not remember or you need to change this password you can do this in the Services section of your account : https://x10hosting.com/panel/services
Your username will be the service username listed for the service.
make sure you are connecting via FTP protocol and not SFTP or similar.