Vampires. Logical starting point would be breakfast.

How well equipped are you with stakes, kindling and fire starting materials? Do you have any handy vampire survival skills? What time of day is it?

switch to a garlic based soaps and shampoos and you'll stand a better chance of not being bitten. Other then that carry what every pyro would with you and you should be fine. You do have a lighter and a can of hairspray right. it's a simply if crude flamethrower after all.

Produce some of that blood serum from Blade that makes vampire blood explode, that shit was radical.

Why are you invading this city? Wouldn't you be better off going to red cross and taking some of their soon-to-expire blood stocks? I promise you it's just as nutritious!

Buy glitter, pretend to be a vampire.

Set everything on fire. Doesn't matter what it is, set it on fire!

Construct ray gun using flashlight and gemstones.
Bring flaming justice to the streets.

Buy a shotgun, load the shells with abnormal ammo. Figure out what harms vampires and shoot it in their faces. If you have spare ammo, tinker and test what works best in ranged combat.

Oh, and stock up on food.

Set about enslaving the vampires so that you may rule the whole city!