How to download YouTube videos?

There is a website YouTube to mp3 juice, you can download youtube videos in mp3 and mp4 formats without registration. There are no pop-up windows, pushing or any annoying ads. You can download even  hours long videos.

How can I make short link of https://canadian-citizenship-test.net/

I created a website about Canadian citizenship test. I want to create google short link, how can I do it?