Hi pavlo.golub,
Thanks for your condolences and praying for our country.
Yes get_header() will outputs the slider which is set for home page. You need to create a child theme and first unhook the functions and then you need to customize the code. There will be a a bit more code of customization so you need to hire a developer to fix it.
example to unhook :-
unhook functions
// Unhook default Thematic functions
function unhook_thematic_functions() {
// Don't forget the position number if the original function has one
remove_action( 'interface_404_content', 'interface_display_404_page_content', 10 );
}
add_action('init','unhook_thematic_functions'); // removes the header content by using hook interface_header
add_action( 'interface_404_content', 'interface_child_display_404_page_content', 10 );
function interface_child_display_404_page_content() { ?>
<div id="content">
<header class="entry-header">
<h1 class="entry-title"><?php _e( 'Error 404-Page NOT Found', 'interface' ); ?></h1>
</header>
<div class="entry-content clearfix" >
<p>Thank you</p>
</div><!-- .entry-content -->
</div><!-- #content -->
<?php
}
Thank you!