First thing first, you go to the projects repository and fork it using the button shown in the figure below.
After that, you will be redirected to the page of the forked repository. You will also be given a URL for the forked repository as shown in the figure below.
Now, you create a new director, go there and type the following commands:
$ git init
$ git remote add origin [the URL show above]
$ git pull -u origin master
And, that's it!