Buddhism is a non-theistic religion, meaning that the nature of God is not pertinent to Buddhist teachings. In Buddhism, gods do exist, but are largely imported from early Vedic (Hindu) teachings. However, the gods play minor roles in Buddhism as protectors of the Buddha and his teachings, and do not serve as "creators" in the sense normally found in Western, Abrahmic, religions.
Additionally, in the six-levels of rebirth found in Buddhism, the highest of the realms is the realm of rebirth as a god-like being, or deva. Beings who are especially virtuous or generous may be reborn in this state. However, the Buddha cautions that this state of rebirth, like all states, is impermanent, and is not the end-goal of Buddhism. Buddhism seeks emancipation from the entire cycle of rebirth.
With regard to origin of existence, Buddhism does not attribute this to a Creator. Buddhism does state that the origin is unknowable, but has existed for eons (beyond the current Universe), and is propelled into continual existence by ignorance and craving, which generates more karma.