Changing the footer text with the Ample theme

Hi
Please can you help me I am new to WordPress and want to change the footer text in the Ample theme. I am not using a Child Theme – do i have to? Is that essential?
This is the code in the footer.php:
<?php
/**
* Footer Section for our theme.
*
* @package ThemeGrill
* @subpackage Ample
* @since Ample 0.1
*/
?>
</div><!– .main-wrapper –>

<footer id=”colophon”>
<div class=”inner-wrap”>
<?php get_sidebar( ‘footer’ ); ?>

<div class=”footer-bottom clearfix”>
<div class=”copyright-info”>
<?php do_action( ‘ample_footer_copyright’ ); ?>
</div>

<div class=”footer-nav”>
<?php
if ( has_nav_menu( ‘footer’ ) ) {
wp_nav_menu( array( ‘theme_location’ => ‘footer’, ‘depth’ => -1 ) );
}
?>
</div>
</div>
</div>
</footer>
<i class=”fa fa-angle-up”></i>
</div><!– #page –>
<?php wp_footer(); ?>
</body>
</html>

Thanks for your help