I am looking for a certain page within a specific domain name, but I do not know what they named that page. Is there a way to see the names of all the pages within that site or perhaps look through an index or parent directory? For example, I successfully guessed two of their pages (other than their main page), suffixed .com/audios and .com/conferencecalls, but I am unable to guess their training page. They have no links on the main page to see these other pages. Any tricks to do this? Many thanks!

There are some softwares like HTTrack which allow you to download the entire site.

Just try using that software. there you'll have entire of the site in your local disk & then easily you can go through the file names.