Never played world of darkness, nor have I been a DM before, only a player, but an important thing to keep in mind with starting a session is to try and not seem nervous and encourage your players to engage if they don't do so right off the bat themselves. This of course mostly applies if your play group is playing the game more for the role-playing than the strategic battling. 
When my group was just starting out a guy in it that had never even played a single game of PnP wanted to take a shot at being the DM, and ended up just about hyperventilating in front of the players with trying to start the game, I don't think he was quite comfortable in his own ability to make himself silly.
To be able to not take yourself too seriously is a big factor to playing PnP's and especially as the DM who may have to make up many quirky and exotic characters. Our campaign started with just about everyone sitting silent after the DM having nervously said that we'd been dropped off at a crossroads, with us having hitched a ride in a caravan to get to a local city, and the caravan dropping us off at a split in the road where they had to take a different turn. Being rather unbashful myself I kicked things off with an extremely corny line that went something like "I, the paladin of Bahamut, Erias Thorne, will be heading straight to the city from this point to visit the local temple. Any one of you wishing to join me for the added security of traveling as a group is welcome to tag along, just state your name and intent and if I agree with you, we'll be able to travel together." something basic to get people to open their mouths and possibly introduce their characters and give you an idea of what kind of person they are.
If I was DM-ing I'd probably have the group start up together, traveling for some reason that would be fitting, and if no one took the initiative I'd have an NPC of some sorts come up to them and start asking questions, could be something like a guard on patrol around the countryside, looking for suspicious characters to keep the roads safe. And if I had a good grasp of the people playing, I'd have the guard talking to whichever player I felt was the least shy, at least to begin with. Just get the players feeling like they're not being foolish by acting it out. 
Later down the line you can just start a campaign with your players, drop them in a random location, and you'll have one player playing a magical cat that can turn into a humanoid form, responding in "meow"s to anyone trying to talk to him while in cat form, another playing a hyperactive 15 year old farm-girl who giggles and squeels, an extravagant sounding businessman with a habit of talking out of his ass with authority he doesn't have, and so on and so on. (BTW: All of these are characters in my current GURPS game, which has a medieval magical setting. And yes, one of these characters is mine... XD) And those players will start exploring and seeking things to do all of their own initiative.
Just basically, don't just drop them into a town, make an evil laugh and yell "AMUSE ME!" out of the top of your lungs. At least not to start with, though you could do that later on, some sessions down the line. 