These are not at all final, but here's some alliances I suspect. Submitters, feel free to advertise what your Tributes are looking for alliance-wise. If you send me preferences I'll add them to the first chapter so people can seek each other out.
Crows: Walcott, Castiel, Fleur, Vulpes, Visenya, Linden,
World's Worst Threesome: Tyler, Deciduous, Jude
Hey You Gaius: Gaius, Toddward, Maxson, Theo W, Valencia, Juni
Circus Alliance 2: Electric Boogaloo: Richard, Elle, Tabitha, Nene
Study and Wit
Gabriel and Dominique
Party Girls: Olivine, Marley, Lottie
Mothless Cult: Sky, Zebulon
Jayhawks: Jay, Logan, Demarcus, Zach, Patrick (?), Mati, Brad
Alysanne and Lacey
Mean Careers: Rapture, Charm, Emma, Margo, Akari?, Tulsi, Cyrene, Diamond Kai, Laken, Faust, Arielle, Talise, Chantal, Jason, Valerie
Nice Careers: Cinderella, Calvin, Amphilia, Jynx, Victory, Tuesday, Siren
(Nice and mean careers are just me putting some logical teams together. They might move as people request them)
Knew Each Other Way Back: Chrysolite and Shale (paired by me since older Careers probably feel overwhelmed- might move)
Crack Pairing: Fable and Jessie, Arno and Elise (alliance of four)
Zibby and Emmeline (paired by me based on mental strengths- might move)
Dumb and Dumber: Majesty and Arleen
The B-team: Unique, Mahi, Daisy
Munch Ado About Nothing: Callum and Stevie
Tinks' Angels: Jezzebel, Jasmine, Akari? Rachel