The Buddha pointed out that no God or priest nor any other kind of being has the power to interfere in the working out of someone else's Karma. Buddhism, therefore, teaches the individual to take full responsibility for themselves. For example, if you want to be wealthy then be trustworthy, diligent and frugal, or if you want to live in a heaven realm then always be kind to others. There is no God to ask favors from, or to put it another way, there is no corruption possible in the workings of Karma.
Do Buddhists believe that a Supreme Being created the universe? Buddhists would first ask which universe do you mean? This present universe, from the moment of the 'big bang' up to now, is but one among countless millions in Buddhist cosmology. The Buddha gave an estimate of the age of a single universe-cycle of around 37,000 million years which is quite plausible when compared to modern astrophysics. After one universe- cycle ends another begins, again and again, according to impersonal law. A Creator God is redundant in this scheme.
No being is a Supreme Savior according to the Buddha, because whether God, human, animal or whatever, all are subject to the Law of Karma. Even the Buddha had no power to save. He could only point out the Truth so that the wise could see it for themselves. Everyone must take responsibility for their own future well being, and it is dangerous to give that responsibility to another.