An indispensable thing never has much value. - Russian proverb
If you're using a Mac or you're using the Ubuntu operating system find a program called Terminal and open it. You can skip the next section about Windows.
If you're using the latest version of Windows 10 you should enable and install Bash on Ubuntu on Windows. You can find the installation guide from Microsoft here.
If you don't have the latest version of Windows 10 you should download VirtualBox and then set up the latest version of Ubuntu with VirtualBox. Instructions for doing this tend to change slightly over time, so I suggest using Google to search for "how to install Ubuntu on Windows with VirtualBox" and then you can follow the instructions that you find.