Our current theory states that the space and time itself has started at this “point”. There is no concept of before or nothing that is compatible with our understanding and what have happened. It is not intuitive at all. There is no such thing as before time has started, since “before” itself is referencing time. Same goes for nothing. So it’s not possible for me to answer your question to yours or mine satisfactions. To help us understand in more abstract ways, we can potentially think in terms of dimensions. My unscientific and backed by no data speculation tells me that perhaps our set of dimensions came into existence at that “point” 🐶🐾🫡