HTTP Status 403 is a response from the server stating that the client has insufficient permissions to access the resources found at the url. You should check your /var/log/apache2/error.log to see the cause of the error.

As for the file permissions, double check that the directory you are serving from has group read permission for www-data.

The fact that you are receiving this response means your setup is working, it just has wrong settings. Post what you find in the logs so we can help you more.