You will sometimes need or want to interact with the operating system via command line terminal (shell) tools like csh, bash, zsh, Powershell, or even the much older MS-DOS. There is a lot you can to with these tools. For now, be sure you are familiar with the basics of directories, reading/writing/removing/moving files, executing programs and commands, filepaths, file permissions, and using program/program inputs and options.
Watch the tutorial appropriate for your computer:
Mac OS Terminal Beginners Guide
Basic Powershell Commands For Beginners (Windows)