Buddha refused to talk about metaphysical speculations, because they would not be helpful in mastering this actual life.
Perhaps you know his story of the man being hit by an poisoned arrow. For him it is not helpful to know the parents of the shooter, but to remove the arrow as soon as possible.
To reach the goal of your life according to the Buddha you have to accept two major principles of life:
- Dependent Origination (sanskrit:Pratītyasamutpāda, pali Paṭiccasamuppāda)
- Cause and Effect (sanskrit Karma, pali Kamma)
If you combine the two you see that there cannot be a beginning of consciousness nor can it end. That's the reason that "you" did not appear from the vacuum and that "you" will not disappear without a trace.
The question is what is that "you" that is subject to these laws. It's the topic of the well known zen koan of "your face before the birth of your parents". But like any other koans you have to "find" your own "solution" of it. Then your questioning will be satisfied.