HTML if url present export as href link - html

Question

I"m working on a wordpress site and I don't have much experience with php. On wordpress you can enter a url for the site. I need help with creating an if statement as if a url is present the links to the url entered in on wordpress.
How does it works in wordpress when a user can input a url on different icons. If they do the icon needs to be clickable like href.
Here is the code:
<div id="legend">
<div class="text-center">
<p>As we continue to track performance and goal achievement, TBD spaces will be filled in with <br />content meant to support and react to continuing progress and opportunities.</p>
<ul>
<li class="oem-event"><span>OEM Event</span></li>
<li class="fa-icon"><i class="fa fa-search" aria-hidden="true"></i> Research</li>
<li class="fa-icon"><i class="fa fa-check-circle" aria-hidden="true"></i> Audit</li>
<li class="fa-icon"><i class="fa fa-lightbulb-o" aria-hidden="true"></i> Planning</li>
<li class="fa-icon"><i class="fa fa-car" aria-hidden="true"></i> Inventory</li>
<li class="fa-icon"><i class="fa fa-commenting" aria-hidden="true"></i> Blog</li>
</ul>
<ul>
<li class="fa-icon"><i class="fa fa-balance-scale" aria-hidden="true"></i> Comparison</li>
<li class="fa-icon"><i class="fa fa-link" aria-hidden="true"></i> Sitelink</li>
<li class="fa-icon"><i class="fa fa-window-maximize" aria-hidden="true"></i> Landing Page</li>
<li class="fa-icon"><i class="fa fa-cog" aria-hidden="true"></i> Custom</li>
<li class="fa-icon"><i class="fa fa-plus-circle" aria-hidden="true"></i> Social Post</li>
<li class="fa-icon"><i class="fa fa-folder" aria-hidden="true"></i> Migration </li>
<li class="fa-icon"><i class= "fa fa-font-awesome" aria-hidden="true"></i> Enhancement </li>
<li class="fa-icon"><i class="fa fa-certificate" aria-hidden="true"></i> WOW </li>
<li class="fa-icon"><i class= "fa fa-google" aria-hidden="true"></i>Google Post</li>
</ul>
</div>
</div>
I've tried this so far:
<?php
// The Regular Expression filter
$reg_exUrl = "/(http|https|ftp|ftps)\:\/\/[a-zA-Z0-9\-\.]+\.[a-zA-Z]{2,3}(\/\S*)?/";
// The Text you want to filter for urls
$text = "The text you want to filter goes here. http://google.com";
// Check if there is a url in the text
if(preg_match($reg_exUrl, $text, $url)) {
// make the urls hyper links
echo preg_replace($reg_exUrl, "{$url[0]} ", $text);
} else {
// if no urls in the text just return the text
echo $text;
}
?>
However I don't think this is the right thing for what I need to do