Can't Find Other Web Pages, Except Index - Where Are They?

I need help with a bootstrap website; my father's website developed by other people. So obviously, I'm a newbie. :)

Inside the file manager, I can't find other web pages such as: About page, Events page, Gallery, etc. Where are they? Are they being hidden purposely?

Screenshot 1

Screenshot 2

Please help me find them.

Thank you for your time.