Download the latest version of Xcode from the Apple developer website or get it using the Mac App Store.
Once you have Xcode installed, open a terminal, run xcode-select --install, and click the Install button to install the required command line developer tools. Don’t worry if you see a message telling you the software cannot be installed because it is not currently available from the Software Update Server. This usually means you already have the latest version installed. You can also get the command line tools from the Apple developer website.