In terms of the showrunners, who will be back for Season 2?
Creator Sam Levinson is largely at the helm of the show -- writing, executive producing, and directing much of the first season based on his own life experiences -- so he should be on for round two. It can also be assumed that Drake, who interestingly executive produced Season 1, will be back, considering the fact that he announced the show was returning ("OBVIOUSLYYYYYYYYY") on social media. But will Champagne Papi get behind the director's chair for Season 2? That's TBD, as well as anyone else who might be on to write/produce/direct the upcoming season, as everything is still hush hush.
What will Season 2 be about?
Euphoria reached a high in its Season 1 finale. Maddy finally ended things with Nate (on the dance floor at the semi-formal, no less); Kat and Ethan put aside their differences and rekindled their romance; and Jules ran away to the city. But highs don't last forever, you have come down from them too -- so it only makes sense that Season 1 also arrived at the most inevitable conclusion for Rue when she relapsed.
The dizzying finale left a lot of questions open, though, so Season 2 might be a bit of a withdrawal from the conflicts that went unresolved. For one, the wellbeing of Rue has been a huge concern for fans, as some thought the final, trippy music-video-like sequence meant that she overdosed, and her narration all along was from the afterlife. It's an interesting theory, for sure, but a bit tangential and one the cast has been quick to squash. Jacob Elordi who plays Nate told IndieWire, "This is the first I'm hearing [that theory]. My feeling is that that's pretty morbid. That's a different show, isn't it? I hope not."
It really does seem like subject for a different show. The direction for Season 2 seems more like it's poised to explore Rue's relapse and struggles with addiction even further, either potentially including a trip back to rehab or following her work towards recovery more closely.
Rue relapsed when she chose to stay home with her family instead of impulsively setting off for the city with Jules, which left fans wondering what that meant for their relationship and where Hunter Schafer's character was headed. Schafer herself told Refinery29, "I feel pretty complicated about it because I wholeheartedly understand Jules' desperate desire to be in a city where queer communities are easily accessible to her, and an energy that matches her frequency is accessible and a train ride away… But I also feel so much for Rue. It gets hard because their relationship was not necessarily healthy all the time and I think they both relied on each other in ways that made them want to be very close and far apart at the same time. But ultimately, like Rue, I understand why she left." As Schafer describes, there's many implications to Jules' "departure," so expect wherever she went and the effects it has on Rue to be explored in Season 2.