Forbidden error?

Can anyone tell me what this error means? Thanks

Forbidden
You don’t have permission to access / on this server.

Additionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request.

This means that you aren’t suppose to see the contents in whatever file that is.

I was trying to set permissions to protect my files/folders whithout the knowledge of “how” to do it and obviously screwed other things up too. What are the default permissions?