How to install this Theme?

[ghost]

Hello,
I am currently learning how to use Jekyll. I love the idea behind Jekyll and would like to use it for my blog. I have already managed to install Jekyll and it works. But I can't manage to install a theme. I have been looking for a nice theme for days and came across this one and I love it. Unfortunately I am too dumb to install this theme. :D

Do I have to fork the theme to be able to use it? And what is the best way to do that?

What is Gulp and NPM and how do I install that?

I hope someone can help me. I really want to learn this.

I am really very very grateful for any help.

P.S.: Sorry for my bad english, i´m from Germany. :)