You need to download Windows 10 and then use the Boot Camp Assistant on your Mac to install a new copy of Windows. You should run Windows 10 on Mac especially if you love games.
Yes, it is possible to run Windows 10 on Mac. Once you get used to the operating system of Apple, whenever you use a Windows computer you will miss the keyboard shortcuts for Mac and especially the useful gestures of the trackpad or the Magic Mouse. One of the main reasons why macOS is better than Windows is that your productivity will be improved.
Frequently Asked Questions Is Mac OS better than Windows?