error message when upgrading

I’m trying to upgrade to 2.7. and I feel like I’m in over my head. I tried to follow directions carefully, but when I try to log in I get this error message:

Failed opening required ‘../wp-load.php’ (include_path=’.:’) in /var/www/vhosts/my website.com/httpdocs/wp-admin/admin.php on line 7

I’m assuming that I need to give more info in the path, but I don’t know how to do it.

Thanks for any help,
Patricia