To add an icon to the menu bar you will have to add a new class to your menu item.

To do this you will have to:

1. Head over to Appearance -> Menus

2. From Screen Options make sure you have the CSS Classes selected

3. You should be able to see the CSS Classes (optional) field under the menu item. In there first add menu-icon and then add the icon that you want

The available icon classes are: home, diet, before-after, pages, recipes-book, our-team, contact.

So let's say that you want to add a blog icon. in this case in your CSS Classes (optional) field you will have this:

          menu-icon blog

If you want a recipes book icon you will have this:

          menu-icon recipes-book

And so on.