mostly this kind of error is caused by missing an .htaccess file in your root wordpress directory ,
Please check that
if . htaccess no available create a new on in root of wp and past that default Wordpress configuration.
# BEGIN WordPress
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
# END WordPress
