Do you have a video or tutorial to edit the main-slider
(OrionThemes) Revolution slider widget is used only to display a slider. To create/edit a slider go toRevolution slider settings, located in the WordPress dashboard. There is an extensive documentation on Revolution slider available here: https://www.themepunch.com/revslider-doc/first-steps/ and also video tutorials here: https://www.themepunch.com/faq/slider-revolution-beginner-video-guides-tutorials/
This should help you get started.