To find the configuration file for Teeworlds, you can read this guide. If you want to configure the client, check out Client Settings. If you want to find the client commands available, see Client Commands. The client configuration file is always called settings07.cfg but located in different locations depending on the operating system.
Run the file called config_directory.bat, that can be find in the Teeworlds directory, or enter %APPDATA%\Teeworlds in an Explorer window.
The config file is located in ~/.local/share/teeworlds/.
The config file is located in ~/Library/Application Support/Teeworlds/.