They are in the bar where vampires, donors and humans can hang out. There are two kinds of places here: the main hall where anyone can sit or drink and private feeding rooms. They usually reserve for the higher ranked vampires or those with more money (and Scaramouche is the one of them so he has his own room there) If you wanna be a donor you have to communicate with another vampire who would be interested in your blood. First of all you have to sign a contract and then get started.