webserver - How to download all HTTP files from a server

I have to do some work on one website, for example example.com, but I need to acces some HTTP sites (example.com/example.htm, example.com/example2, …)

I don't know how are they named) but I dont know how to access them. Is there a way I can download everything from that FTP server that is not mine?

I have no access to the FTP server. Imagine that it is blank website with no buttons or anything (example.com), but there are some files and websites on that same server. I need to know all these files.