There is no "center" of the big bang. It isn't an explosion; it's the expansion of space-time. The big bang occurred everywhere. The matter derived from the energy of the big bang (the two are equivalent). Science is currently speculative as to the source of the energy. One possibility is that the negative gravitational energy of the universe precisely cancels the positive energy of the matter plus radiation in the universe meaning that there was no energy actually created in the big bang. (zero total energy before and after) Similar to the question of the origin of life WRT evolution, the origin of this energy is immaterial. The big bang attempts to describe the development of the early universe after the expansion of space-time began. It doesn't cover why it occurred or where the energy came from, etc.
Space-time had no beginning. The origin of the energy is material, because the energy precides this creation of the universe myth. This energy indicatest that something precided this event therefore it is not a creation of the universe, as the universe was already here.
Like Columbus discovered America, which was already here and had people living in the woods..