As far as I know you can't download Blend alone without also downloading visual studio. But you get it when you install any (not 100% sure. It works with vs2015) version of visual studio community. The community version of visual studio is free so you don't have to pay for Blend. You'll also get Blend with the paid versions.
You can download the visual studio versions here: https://www.visualstudio.com/downloads/download-visual-studio-vs
After you install visual studio you can find a shortcut to your Blend in the Start Menu folder or at "C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\Blend.exe" (if you installed visual studio in the default location)
Hope this helped you