Changing widgets on home page

Using theme Revival. Had tutorial week ago…went by too fast, could not take enough notes! Anyway, there are three images w/text below “Slider” that I cannot figure out how to change…although I eventually did edit them but only the title and image published or “Updated”…the text is still Latin gibberish. Perhaps I didn’t do it legally. Where do ya do it properly???
When I go to Widgets the only choices for edit/addition are Right Side Bar and Front Page Bottom. What about editing the Slider and those other boxes???
I have more questions. Could not find a you tube tutorial on Revival or any other sources of How To. I need the very basic, simple stuff that whizzed by during one-on-one tutorial which only made sense in the moment and maybe didn’t cover everything anyway..not advanced adding on stuff. THX, Mona