WordPress Button-on-Hompage问题| 简单修复？ （不能使用Customizer ... PHP编辑？）

(Total newbie here and not a web developer by any means. Thought I'd try and ask since my Google queries typically bring me to this site anyway.)

I am using a WordPress theme, Corporate Plus. The button on the homepage will not take whatever link I input through the Customizer.

Preview of what I'm seeing (the "Let's Get Started" button): http://ruleyourcompetition.com/?customize_changeset_uuid=105d9013-cf7a-4d54-9808-0039f71eb423

Per another thread I found here on StackOverflow, it seems like I can edit the function.php file with:

function custom_excerpt_more($more) {
    global $post;
    return '<a class="moretag" href="'. get_permalink($post->ID) . '">' . __("Your Read More Link Text", "your_theme_slug") . '</a>';
}
add_filter( 'excerpt_more', 'custom_excerpt_more' );

However, I'm not sure what changes to the above code I might need to make, if this is the recommended way to go about it. I tried the simpler fix mentioned in the replies on that other thread, but that didn't seem to do the trick.

Trying not to break the site. Can anyone recommend advice?

Thank you!