We have set up a lightning community. When I access it at https://mycommunity.cs1.force.com/s/login, I see an Experience (Community) Builder lightning login page. But when I try something like this (as unauthenticated user) https://mycommunity.cs1.force.com/something, I get the standard Page Not Found (404) Visualforce page.
A logged in user would see internal org:
Obviously this is not user friendly and external users would not be happy to see it. So what is a best practice around this situation? How is it usually set up?