Find this code in header.php file

header.php

<div class="logo_container">
<span class="logo_helper"></span>
<a href="<?php echo esc_url( home_url( '/' ) ); ?>">
<img src="<?php echo esc_attr( $logo ); ?>" alt="<?php echo esc_attr( get_bloginfo( 'name' ) ); ?>" id="logo" data-height-percentage="<?php echo esc_attr( et_get_option( 'logo_height', '54' ) ); ?>" />
</a>
</div>

from above block of code rplace 
<a href="<?php echo esc_url( home_url( '/' ) ); ?>">

with 
<a href="https://www.target-link.com">