Vampires, let’s look at the definitions as set forth by the known dictionaries:

Merriam-Webster

1: the reanimated body of a dead person believed to come from the grave at night and suck the blood of persons asleep
2:
A : one who lives by preying on others

B : a woman who exploits and ruins her lover

Dictionary.com

1. A preternatural being, commonly believed to be a reanimated corpse, that is said to suck the blood of sleeping persons at night.
2. (in eastern European folklore) a corpse, animated by an undeparted soul or demon, that periodically leaves the grave and disturbs the living, until it is exhumed and impaled or burned.
3. A person who preys ruthlessly upon others; extortionist.
4. A woman who unscrupulously exploits, ruins, or degrades the men she seduces.
5. An actress noted for her roles as an unscrupulous seductress: the Vampires of the silent movies.

Their definitions, dictated by Hollywood lore, and bits & pieces of various folktales, are far from the truth.

Let's start with the definition they suck blood, yes, Sanguines suck blood, but various species of Vampire are known to suck more than blood; energy, water, brains, & souls.

The latter are both really ancient in documentation & legend.  The brain-eating Vampires were said to have extremely long tongues with pointy ends that could enter the victim through the mouth, nose, or ear, & remove the brain in small pieces.  Their bite would paralyze the victim, but not put them out of their misery while they were preyed upon. In some recordings it wasn't a paralyzing bite, but paralyzing content emitted from the mouth into the nostrils of the victim.

The soul-eating Vampires were supposedly reanimated minions of a grim reaper fountainhead, who would send out the Vampires to collect souls, sometimes from still living people who were especially bad, at which time the victim would become virtually comatose, or zombie-like.

The blood, energy, & water sucking Vampires are the most well-known, with aqua Vampires being the least favored of the three.  The aqua Vampires were certainly among the more ruthless, and typically lived in areas where water was little accessible, after be-falling a fate which robbed them of their natural surroundings.  They were not well-documented past the medieval ages which begs the question of extinction?  Or, they were simply absorbed by other bi-ped species?

The world of Vampires is not a small one, almost every known culture has a Vampiric entity that lived & thrived during various points of civilization.  Some animals, some bi-ped humanoids, some ghostly, & some just plain invisible.

Vampires don't just hunt at night, granted the cloak of darkness is good for any deed where you don't want to be caught, but various predators had various means through which they'd get their prey.  Some of the more ruthless would snatch babies, small children, the weak, or the elderly in broad daylight.  Most people in ancient times were in their homes by nightfall, they weren't out wandering around in the dark.  There weren't street lights back then, if you were caught out in the dark it was pitch black.  Despite popular consensus, not all Vampires can see in the dark like cats.  Some races were known to be able to see in pitch black conditions (new moon stages, no external light), however most races could see well in the dark only if provided some external lighting.  And, Humans, Elves, Giants, Dwarves, & other bi-ped races were not known for their night vision capabilities.  Therefore, people killed under cloak of darkness were usually said to be asking for it, or had it coming.

Of course, Vampires weren't the primary predators people were running indoors for, there were plenty of animal predators known to attack at night, not to mention criminals of all bi-ped species who robbed, raped, & maimed, so all-in-all people were overly cautious at night, which meant Vampires couldn't be held to night-only hunting if they wanted prey that was not nocturnal.  Vampires, contrary to Hollywood (and apparently dictionaries) didn't just feast on human blood, they would drink the blood of anything that had blood.  And some Vampires contend the taste of blood varies by species & some prefer a variety, or prefer the taste of the blood of one prey over another.

Most Vampires lived in communities, sometimes very small ones, sometimes in thriving, city-sized ones.  The formation of clans was on a case-by-case basis, & not all Vampires had to belong to a clan, in fact for hundreds of years there were no clans, because there was no need for them.  Clans are specific to location and/or purpose, and formed much later in Vampire history.  Most strictly-Vampiric civilizations operated much like other civilizations of other bi-peds at the time; with a governing person (like a king/queen, dictator, emperor), a governing body (like a government), or through mutual exchange (bartering system), in all cases there were rules which had to be lived by & typically a police-type force that protected the citizens from themselves & outside sources.  At no time were they all coffin-bound, in fact, coffins were little used as most times in ancient societies the dead were burned.