[@Slendy]
Your options are as such:

Freelance is willing to accept even the most brutally insane monsters, as long as it helps them fight the Purge. The Director, leader of Freelance, has a personal vendetta against the Purge and already employs a psycho cyborg vampire monster. They would happily employ you if you turn out to be useful.

Gabriel is gathering an army of vampires in order to make a final assault on humanity. He plans to lead the vampires in glorious conquest of the planet, lead by an army of brainwashed vampire ninjas. This option would most likely provide the most slaughter, but the Director is currently on Hawaii and might be making an alliance with Gabriel.

Dawn is attempting to create peace between humans and vamps. They're mostly hippies, and lack military power.

Alternatively, you could run solo. Although that's a sure-fire way to end up getting killed by the Purge. They're trying to equip every doorway with vampire scanners, and every street corner with holy water vapour dispensers. Effectively the capability to wipe out all vampires in a city at once without harming humans. As such, a number of cities are already impossible for vampires to live in (including Oklahoma).