Certainly, the best evidence currently available indicates that the universe began to assume its current form about 14 billion years ago (the “Big Bang”). The problem is that no one knows what happened before this event.
Obviously, the “stuff” that began to expand existed before the Big Bang. We don’t know where this “stuff” came from, whether it always existed, whether it had expanded into a universe before and then contracted, or whether it makes any logical sense to talk about time (and “causes”) before there was motion and time. We simply don’t know.
If you do have any evidence that might suggest an answer, please let us know. If you do, you will be world famous and highly regarded in the scientific community in a very short time.