>So vampires in nWoD are just standard base vampires, and all of their differences are social or something?
Nah, Clans still do everything you'd expect. It's just that what a Clan represents is now different. So the 5 main VtR clans are Daeva, Gangrel, Mehket, Nosferatu, and Ventrue. You'll recognise three of those names but VtR Clans aren't VtM Clans and the similarities they share aren't really for quite the same purposes.
The 5 clans broadly fill each major archetype of pop culture vampire. Daeva are seductive social predators, they're the sexual/sensual side of vampire myth. Gangrel play to the animalistic nature of vampires, their savagery, and their shape shifting abilities. Mekhet are secretive and shadowy creatures, they're the vampires who lurk in the dark unseen yet seeing all. Nosferatu are the grotesque monstrosities, but also the unsettling or obviously inhuman vampires. Finally, Ventrue are the aristocratic vampires, vampires as a metaphor for the inequality of wealth and power that is often prevalent in myth, and those who bend you to their will. Each is designed to fulfill a clear archetype without tying you to it totally, you get an awful lot of flexibility in each clan so you don't have to worry about "staying true to the clan" or whatever.
Each Clan still has it's set of three Disciplines one being unique, they each get a unique Bane, and there are bloodlines that only some Clans can join. The Disciplines for each are as follows. Daeva get Celerity, Majesty, and Vigor. Gangrel have Animalism, Protean, and Resilience. Mekhet get Auspex, Celerity, and Obfuscate. Nosferatu have Nightmare, Obfuscate, and Vigor. Finally Ventrue get Animalism, Dominate, Resilience. Three things you'll notice there, Potence was renamed to Vigor, and Fortitude was renamed Resilience, and most importantly each Clan gets a unique Discipline. Also Discipline design is so so so much better in 2e than VtM it's insane. I can find a comparison between 2e and V20's takes on Protean if you want to see that, massive differences.
>Don't tell me the Tremere are gone too.
Glad you asked. The other oWoD Camarilla Clans either don't fulfill an archetype, are overly restrictive in theme given VtRs push for more flexibility in how Clan is a facet of your PC, or their theme is so broadly applicable to any major archetype it makes more sense to be represent through Covenants. A great example is Brujah or Tremere, iconoclastic idealism or a bent for the occult shouldn't be the purview of a Clan. Covenents take the place of Sects, the Camarilla is long dead in VtR's setting and as such there is no single Sect you're expected to be a part of. There are 5 major player facing Covenants each with different goals, attitudes, tools, and the like.
As a super reductive take on those 5. The Invictus fufill the oWoD Camarilla role, they're all order and tradition to safeguard the Masquerade. The Carthian Movement is inspired by the Anarchs, more modern and experimental and open to mortal solutions. The Lancea et Sanctum is the vampire church, they're a neo-feudal theocracy that think God cursed Longinus to be the first vampire. The Ordo Dracul, founded by Dracula, are a mad-sciency Victorian secret society that struggles to transcend the Curses through eldritch alchemies and rites. Then there is the Circle of the Crone which are a pagan cult that venerates female divinity, painful change, and the old ways remixed for the modern world. Each city will have Covenants in different populations, with different alliences, and some might not have any claim to some places at all.
Covenants play a much larger role than Sects in VtM and now offer a large secondary point of customisation. Your chosen combination of Clan and Covenant massively impacts who your character is. Clan is still super important but it's not quite the be all end all, and Covenants give a huge additional purview for RP and narrative expression. The interplay between Clan and Covenant lend you a lot more customisation than any single clan does.
Now the Tremere are back where they belong (as Mages) you are way more free to explore vampire magic now. There are two flavours of Blood Sorcery to work with, whether its the malevolent and wild Crúac that draws upon the Beast to invoke primordial gods, or Theban Sorcery that leverages the power of the Curse through zealous faith and deliberate ritual. Then you've also got the Ordo Dracul and their Mysteries of the Dragon that seek to transcendence of the Kindred form, mastery of their banes, control of the Beast, and more through occult alchemy and experimentation. So instead of that being just all one Clans thing you can now see how multiple clans would adapt to it. How a Gangrel might interact with those systems and philosophies is different to how a Ventrue might. The cool thing about being Tremere was magic and then basically just political, that stuff works way better as a Covenant/s than a Clan IMO.