covens, clans, and packs.

to sum it all up, clans, packs, and covens are how werewolves, witches, and vampires are 'organized'. clans are reserved for witches, packs for werewolves, and covens are for vampires.
with that out of the way, the list and description of the groups are located below.
in your application, you'll have to choose the clan/pack/coven that suits your character the most. obviously, a werewolf can only be of a pack, not a clan or coven; the same for witches and vampires; they must stay with their own kind.
there's also the choice of your character being a loner. this means they choose not to socialize with or have been casted out of one of the groups. there could be a group of nameless loners or an individual; beings of different species and clans may socialize with humans - however, please keep in mind that werewolves and vampires - most of them at least - feed off of humans. this goes with the exception of certain covens and packs. dark witch clans are against humans, also.

vampire covens

Avarice.
The more peaceful group of vampires, this is the coven that exists solely to mingle with humans without much suspicion of their true race. They feed on animals rather than humans and cannot come out in the bright sunlight, though the foggy, overcast weather of Hollywood has become a habitat for them, allowing them to roam the streets twenty-four hours a day. Despite the fact they feed on animals, their senses are still aroused by the smell of human blood - this is why they avoid intimate relationships with humans. It is strictly against the coven's code to have intimate relations with a human being - or to infect them and change them into a vampire without their complete consent. They're completely against attacking innocent human beings, and consequentially against the Devenseduire coven. The only consequence for breaking the intimacy or inappropriate 'breeding' (biting) code is exile, where the subject is forced away from all that belong to the coven and forbidden to communicate with anyone that belongs to said coven. That is - if the leader finds out.

Devenseduire
If you're a human that's afraid of vampires, this is the coven you have to fear. Merciless and manipulative, also greedy, the Devenseduire coven is the organization of bloodsuckers that feeds continuously off of human blood. They are bloodthirsty and mercy-lacking trackers that never lose a scent when they find a human particularly delectable-looking. When they drain a human of its blood, they abandon it to dwell in its wonder of undead lifestyle without any guidance. A lot of the Avarice clan are Devenseduire victims taken underneath the wing of the gentle but strengthened coven of vampires. There are fewer vampires in the Devenseduire clan than the former, although what they lack in people the power-hungry, proud clan makes up for in strength. Human blood is more enriching and in a way 'higher in protein' than animal blood - which is why they seem, and are, more powerful than the former coven.

witch clans

Argenpur
Argenpur is the alliance of witches that has chosen a kinder lifestyle, tending to wounded humans and immune, like all other witches, to the venomous bites of both werewolves and vampires. They have the power to heal most wounds and are admittedly equal in power to the dark Peragwen clan. Most of them are complete humanitarians. They seek out people, animals, and places that need fixing or assistance and do everything they can to help. If they're not overachievers, they're usually just neutral - capable of magic and willing to constantly feud with their unkind brothers.

Peragwen
Ah, Peragwen. Choosing an alliance with this clan is choosing an alliance of pure evil. They side with the dark werewolves and vampires, specializing in dark magic and indifferent to society and 'worthless', helpless people that lack the strength to mend their own wounds. They loathe the Argenpur, naturally, and in the broad daylight have magical duels with the other witches and wizards. Like the Argenpur they aren't affected by vampire venom, though they're incapable of killing a vampire without hordes of them attacking a single one. Even though the venom doesn't affect them, they can still be brutally murdered by one of the monsters. Though they are filled to the brim with pride and dignity, a lot of the dark witches are cowardly.

werewolf packs

Disuagio
Disuagio is a werewolf pack that was the first ever founded, centuries ago. Until the mid 1900s, the group of so-called 'monsters' lived in actual harmony with one another, rarely attacking when under control of themselves and trying their hardest not to attack humans. However, around 1955 an immense group of the canine humans broke away from Disuagio, their intentions of attacking humans and in turn being attacked. The Disuagio pack has since then mericlessly sworn the opposing, abandoning pack their enemies, able to smell the evil on their fur from miles away. They rarely attack humans and feed on animals, with intense senses of smell and hearing.

Rottura
The Rottura is a large group of werewolves that broke away from the Disuagio pack in the 1950s. They mercilessly attack and feed on humans; you could call them cannibals for this, though when they feed they're usually not in their human forms. You can tell they're Rottura wolves because of the hairiness in men and the slenderness of the women; ironically most female Rottura werewolves, though strong and stable and as capable as the males, are slender and by first glance lack any muscle.They're built for the hunt, for the kill.