Adding Arrow to Site Navigation

Site URL: https://www.marissamae.com/

Hi all! 

I'm trying to find a way to make it obvious that people need to scroll down for more content on this page of my site. I was hoping that I could add an arrow to the center bottom of the page, but am not only having a hard time finding the proper coding to insert, but also don't know that the arrow would show up against my shirt. My home page layout matches with this page layout, so I don't want to shrink the size of the photo or change the photo arrangement. I need to find a solution that can work with this current layout. 

Any recommendations would be greatly appreciated!  

Thx! -Marissa