Creating and changing items on the home page

I feel like an idiot because I can’t seem to figure this out on my own or find any information about it anywhere. (but nobody else seems to be asking it either so I feel like I’ve missed something very obvious)

I’m trying to set up my home page like one of the home pages shown in the demo. For example A slider, then 3 boxes that have a little text/an image or icon/link and then text and photo.

I’ve obviously set up the page I want in the READING settings so that it is the static home page but I can’t figure out where to setup and change these pieces so they show up on the front page.

Any thoughts that will point me in the right direction would be very, very welcome!
Thank you so much!
Beth