Hide elements based on their Page or class using JS or JQuery

I’m using Jquery FullPage.js for scrolling pages inside website.
How can I write a simple js script, where, for example, if we are on the firstPage the elements will dissappear, and if we are on the other pages fixed element will remain?
I just don’t know JS well, but the logic is like – if firstPage element display none – else display block.
Thank You