Hi ribo
You can edit this file: /templates/ja_mixstore/html/com_contact/contact/default_address.php
and add the icon as you wish.
For example, I will add the map marker icon before the Address:
<dt>
<span class="<?php echo $this->params->get('marker_class'); ?>" >
<i class="fa fa-map-marker"> </i> <?php echo Jtext::_('TPL_STREET_ADDRESS') ;?>
</span>
</dt>
you can add the same for other element as you wish.
Regards