[@Wraithblade6]

Vampires are mystical creatures like dragons, fairies and so on. They have always been, much like humans and every other creature.
The world that this is set on isn't Earth, but a created fantasy world like the Eldar Scrolls or TP's Disc World. 

The vampires are very hardy, but not invincible. The only way the vampires are able to seem to live forever is that they drain the life-force of other creatures, which is why its important that they keep humans alive and as well as they can. Lack of life-force will cause vampires to go into a mortise-hybantive state.  

As for the sun exploding, the age this is set in is around steam-punkish technology and understanding. They have little knowledge of stars exploding.

For human day to day lives, they live in small camps/villages which often run much like they did, there's taverns, brothels and such. However when the work bell rings, everything stops and the humans will go to their assigned jobs.

There are one or two villages on the outskirts that are still human controlled, though it is difficult to find them as they try to stay hidden. 

And many of the original Vampires from the first uprising are still alive, in fact every house master is one of them. If you wish to play as a Vampire from 4000 years ago you're more than welcome.