How to make the most recent post appear first?

Hi,
I would like to know how to make the most recent post appear first.
Reading earlier posts on this subject, I’ve tried including
“<?php query_posts($query_string . ‘&orderby=date&order=ASC’); ?>
<?php while ( have_posts() ) : the_post() ?>”

in the html code but it doesn’t work. I use the twenty-ten theme, but changing to the wordpress classic theme does not fix the problem.

My site is here: https://scc-temp.co.uk/wordpress/

I would be grateful for any useful help,

Cheers,

Lotte