How to Load Scripts and CSS for Admins Only When Editing or Adding Posts

you want to use admin_print_scripts-(page_hook) and admin_print_styles-(page_hook), so in your case:

add_action('admin_print_scripts-post.php', 'call_my_function');
add_action('admin_print_scripts-post-new.php', 'call_my_function');

add_action('admin_print_styles-post.php', 'call_my_styles_function');
add_action('admin_print_styles-post-new.php', 'call_my_styles_function');