Configuration File
Generally, Cert Warden should start up fine without making any changes after installation and the default configuration is likely fine for most people. However, there is a config.yaml file in the application's /data folder that you may wish to review and change.
The default configuration values can be viewed here and an explanation of all possible options can be viewed here. These links are to the most recent versions but version specific copies of the same files are included with the Docker image and installation packages.
There are a number of configuration options you might want to change such as which address to bind to, port numbers, etc. Don't worry about configuring your ACME service, keys, accounts, certificats, or challenge methods. All of this can be done in the GUI after your first login.