Yesterday, before Superman and Lois had officially announced the casting of two teenage sons for the titlular couple (Jordan Elsass and Alexander Garfin as Jonathan and Jordan Kent), rumors started circulating that plot details from the show's pilot script had been leaked online. It's always good to view such rumors with a degree of skepticism, but since Jordan Kent -- a character created for the show -- was rumored to be the name being used, it seems likely that the story has some credibility to it. Among other things, the story suggests that while Clark's adoptive father Jonathan Kent will have passed away, Martha Kent will be alive and serving as a supporting character.
Per According to PrimeTimer, "As the series opens, LOIS LANE is still working at the Daily Planet, but CLARK KENT has just been fired following a massive layoff plan at the journal. His father JONATHAN KENT is no longer with them, while his mother MARTHA KENT is living alone on the farm where he grew up in Smallville. They have twins, JONATHAN and JORDAN KENT, who are thirteen and very different — both physically and otherwise. Jonathan is the popular one, an all-star athlete who’s about to enter the Varsity team, while Jordan is more introverted, anxiety prone, and very much into computers and video games. They don’t know who their father really is… yet. And they may or may not have inherited his powers."
Of course, the idea of Martha outliving Jonathan is pretty standard fare in the live-action arena; the Richard Donner movie, Zack Snyder's Man of Steel, and Smallville all took that approach. If the PrimeTimer reports is to be believed, it seems likely that fans will be seeing a not-insignificant amount of family drama. Besides dealing with Clark being laid off and both of them being incredibly famous and in-demand in their fields, Superman and Lois will reportedly explore Lois's father Sam Lane (previously played on Supergirl by 24 alum Glenn Morshower.
“Lois’s father GENERAL SAMUEL LANE is in the picture and knows about Clark. LANA LANG is also a big part of the show. She’s a banker, still living in Smallville, with her husband KYLE CUSHING, a firefighter, and their daughters, SARAH, who’s fourteen, and younger SOPHIE who’s eight. They are in a dark place: Kyle is a drunk and Sarah tried to take her own life a year ago."
Lana's personal life was a mess during the post-Crisis on Infinite Earths era of the comics, which led to hear seeking out Clark even after he left for Metropolis. Later, she would marry their childhood friend Pete Ross, who sounds like the opposite of the husband described above (he eventually ended up elected Vice-President).
The story also claims that there will be a mysterious stranger who serves as the season's main antagonist and whose identity the audience learns at the end of the pilot. Given the context of this story, it seems likely that "The Stranger" will turn out to be Jor-El, Superman's father, who recently turned out to be significantly less dead than we had believed all these years in the comics.
After rumors that Superman and Lois would get a pilot starring Supergirl actors Tyler Hoechlin and Elizabeth Tulloch circulated last fall, the news broke on the say the Crisis began that the show would instead be ordered straight to series for the 2020-2021 season. The CW renewed almost all of their shows, and ordered two new ones, pretty early this year, likely so that they could bank some scripts in anticipation of a potential writers' strike. A second Arrowverse pilot, Green Arrow and the Canaries, has yet to be ordered officially.