Unfortunately, macOS does not come with development tools pre-installed like on Linux, BSD, and other *nix systems. Luckily, it’s simple and easy to do. Open up the Terminal application (Applications/Utilities/Terminal.app) and type:
xcode-select --install
This installs all of the standard command line tools you should be used to, since it’s no longer an option to do so inside of the Xcode IDE. Speaking of which, you no longer need an Apple Developer account to install Xcode. Simply open up the App Store application, search for, and install Xcode:
All done, start programming away!