Move comment form above list of comments.

comments.php

<?php
/**
 * The template for displaying Comments.
 *
 * The area of the page that contains both current comments
 * and the comment form. The actual display of comments is
 * handled by a callback to generate_comment() which is
 * located in the inc/template-tags.php file.
 *
 * @package GeneratePress
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit; // Exit if accessed directly.
}

/*
 * If the current post is protected by a password and
 * the visitor has not yet entered the password we will
 * return early without loading the comments.
 */
if ( post_password_required() ) {
	return;
}

/**
 * generate_before_comments hook.
 *
 * @since 0.1
 */
do_action( 'generate_before_comments' );
?>
<div id="comments">

	<?php
	/**
	 * generate_inside_comments hook.
	 *
	 * @since 1.3.47
	 */
	do_action( 'generate_inside_comments' );
  
  comment_form();

	if ( have_comments() ) : ?>
		<h3 class="comments-title">
			<?php
			$comments_number = get_comments_number();
			$comments_title = apply_filters( 'generate_comment_form_title', sprintf( // WPCS: XSS OK.
				/* translators: 1: number of comments, 2: post title */
				esc_html( _nx(
					'%1$s thought on &ldquo;%2$s&rdquo;',
					'%1$s thoughts on &ldquo;%2$s&rdquo;',
					$comments_number,
					'comments title',
					'generatepress'
				) ),
				number_format_i18n( $comments_number ),
				get_the_title()
			) );

			echo esc_html( $comments_title );
			?>
		</h3>

		<?php
		/**
		 * generate_below_comments_title hook.
		 *
		 * @since 0.1
		 */
		do_action( 'generate_below_comments_title' );

		if ( get_comment_pages_count() > 1 && get_option( 'page_comments' ) ) : ?>
			<nav id="comment-nav-above" class="comment-navigation" role="navigation">
				<h2 class="screen-reader-text"><?php esc_html_e( 'Comment navigation', 'generatepress' ); ?></h2>
				<div class="nav-previous"><?php previous_comments_link( __( '&larr; Older Comments', 'generatepress' ) ); ?></div>
				<div class="nav-next"><?php next_comments_link( __( 'Newer Comments &rarr;', 'generatepress' ) ); ?></div>
			</nav><!-- #comment-nav-above -->
		<?php endif; ?>

		<ol class="comment-list">
			<?php
			/*
			 * Loop through and list the comments. Tell wp_list_comments()
			 * to use generate_comment() to format the comments.
			 * If you want to override this in a child theme, then you can
			 * define generate_comment() and that will be used instead.
			 * See generate_comment() in inc/template-tags.php for more.
			 */
			wp_list_comments( array(
				'callback' => 'generate_comment',
			) );
			?>
		</ol><!-- .comment-list -->

		<?php if ( get_comment_pages_count() > 1 && get_option( 'page_comments' ) ) : ?>
			<nav id="comment-nav-below" class="comment-navigation" role="navigation">
				<h2 class="screen-reader-text"><?php esc_html_e( 'Comment navigation', 'generatepress' ); ?></h2>
				<div class="nav-previous"><?php previous_comments_link( __( '&larr; Older Comments', 'generatepress' ) ); ?></div>
				<div class="nav-next"><?php next_comments_link( __( 'Newer Comments &rarr;', 'generatepress' ) ); ?></div>
			</nav><!-- #comment-nav-below -->
		<?php endif;

	endif;

	// If comments are closed and there are comments, let's leave a little note, shall we?
	if ( ! comments_open() && '0' != get_comments_number() && post_type_supports( get_post_type(), 'comments' ) ) : ?>
		<p class="no-comments"><?php _e( 'Comments are closed.', 'generatepress' ); // WPCS: XSS OK. ?></p>
	<?php endif; ?>

</div><!-- #comments -->