You'll want to pick up at least two more kegs ASAP. You don't want to finish a keg, then have to wait until you clean, fill and carbonate your next beer. You'll quickly want to establish a pipeline.
Don't use vaseline. Pick up some keg lube, it's cheap and it's food grade. Vaseline (IIRC) can degrade the rubber.
Fermenting: Stout, Pale Ale, German Pilsner
Drinking: Vienna Lager, Saison, Cider
On Deck: IPA, Brown Ale, Pumpkin Ale