To add widgets to your Footer:

Navigate to Appearance → Widgets page at your dashboard.
Drag widgets into Footer Sidebars (Footer-left,Footer-middle,Footer-right)
On the left side, locate a widget that you want to add.
Click on the widget and select one of the options: Footer-left,Footer-middle,Footer-right or Footer-bottom, then click the Add Widget button.

Configure the widget's settings once it is added to the Footer widget area.
When you are finished configuring the widget, click the blue Save button at the bottom.

Widgets used in our demo

Footer Left

1- Widget type: Text

2- Widget type: Navigation menu

Content: Menu created as presented with the WordPress Codex: https://codex.wordpress.org/WordPress_Menu_User_Guide

Footer Middle

Widget type: Text

Demo Content:

<ul>
 <li><i class="fa fa-envelope fa-fw"></i><a href="mailto:contact@mywebsite.com">contact@mywebsite.com</a></li>
 <li><i class="fa fa-phone fa-fw"></i>+33 123 456 789</li>
 <li><i class="fa fa-map-marker fa-fw"></i>8098 Center Street Easley, SC 29640</li>
</ul>

Footer Right

Widget type: Navigation menu