Icons inside navigation via child time might be a bit tricky. You can use this example for copyrights to understand how this editing works.
Create a function.php
file inside your child theme folder and add the following.
<?php
// Replace copyright information from footer-extensions.php
// Remove old copyright text
add_action( 'init' , 'remove_copyright' , 15 );
function remove_copyright() {
remove_action( 'travelify_footer', 'travelify_footer_info', 30 );
}
// Add new copyright info
add_action( 'travelify_footer' , 'new_footer_info' , 30 );
function new_footer_info() {
$output = '<div class="copyright">Your new copyright information. Thanks to <a href="https://colorlib.com/" target="_blank">Colorlib</a></div>';
echo $output;
}
?>
I hope this helps at least a bit.