If you are wondering how to add Font Awesome fonts to your WordPress theme, this is how:

You’ll need to use the code below in your child themes function.php file

Once that’s done you can simply use icon codes your HTML markup

ex :
<i class="fa fa-circle fa-stack-2x"></i>
<i class="fa fa-question-circle-o fa-stack-1x fa-inverse"></i>

Icon┬ácodes – http://fontawesome.io/icons/