Reply To: Change title and add text to comment form

Replace the text values of the code below (ex. “Comment Form Title”) then add it on your Child Theme’s functions.php

function ra_comment_form_defaults( $defaults ) {
     $defaults['title_reply'] = 'Comment Form Title';
     $defaults['comment_notes_before'] = 'Comment Form Text';
     return $defaults;
}
add_filter( 'comment_form_defaults', 'ra_comment_form_defaults' );

To add those asterisks, go to the admin area Settings -> Discussions
then check the Comment author must fill out name and e-mail option.

To change the background color, add this on the theme’s Custom CSS option. Replace the color white (#FFF) with your chosen color.

#respond.comment-respond {background-color: #FFF;}

Read these posts for further info on customizing your theme:

https://ronangelo.com/learning-css-a-quick-useful-introduction/

https://ronangelo.com/use-firebug-to-modify-wordpress-theme-css/