okay i figured it out. a little gnarly at first. you have to go in the classic editor and change pic IDs by hand as the background image toggles only work on the “inner” background image. you can then change the menu that come with the demo to your own that has the desired links to whatever pages you want. what made this odd is the custom css i wrote did not work at all in terms of changing the urls of background selectors. i used inspect to find the main demo page id which (yikes) began with a number, but even when i used tricks like escape characters to target this id selector that begins with a numeral (or other tricks, all of which work elsewhere) the wp preprocessor barfed. once you get the hang of it it’s pretty easy and begins to look like any other plain ol’ point and click page builder.