harnishdesign on "403 forbidden error when I add post in wordpress"

I have fresh & latest word press install . but

When I create & add post from admin side in word press. so create below error.

Forbidden You don't have permission to access /blog/wp-admin/post.php on this server. Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

please let me know. How to fix?

Thanks.