The effect of Captivating Vampireâ€™s activated ability has no duration. You retain control of the affected creature until the game ends, the creature leaves the battlefield, or a later effect causes someone else to gain control of it. It doesnâ€™t matter whether Captivating Vampire remains on the battlefield. Similarly, the affected creature remains a Vampire in addition to its other types until the game ends, the creature leaves the battlefield, or a later effect changes its types or subtypes.
Since Captivating Vampireâ€™s activated ability doesnâ€™t have a tap symbol in its cost, you can tap a Vampire (including Captivating Vampire itself) that hasnâ€™t been under your control since your most recent turn began to pay the cost.
Gaining control of a creature doesnâ€™t cause you gain control of any Auras or Equipment attached to it.