Clickable link: Godot Engine – Download | Windows
That link will take you to the website where you can download Godot.
Click on the tab that correlates to the Operating System in which you are downloading Godot on. Then select the button that correlates to the bit the Operating System is in, either 64-bit or 32-bit.
If you are going to C#, which is another programming language, then download the Mono Version. If not, then download the Standard Version. They are the same, except Mono Version supports C#
Once it downloads, you will need to go into file system right click on the file and Extract the file to a stable version. Once extracted, make sure that the new file is operational by right-clicking the file and pressing refresh. Then you have the executable file to open and run Godot right there.
Now the fun has just begun!