Error 403:when loading site

I've lite cart install but I go to the site &get this-
Forbidden
You don't have permission to access /index.php on this server.
Additionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request.site+http://chattyvalley.org

What did you recently change? Was it htaccess rules? File owner or chmod?

I am not sure

Don't think I touched those