A few physics things:
Matter and energy can change into each other. Thanks Uncle Albert.
Space is not linear nothingness. Carl Sagan's old analogy is to think of a balloon which is a 2D surface in a 3D environment. A fair way of thinking about our universe is to think of a 3D surface in a 4D environment in a similar way.
Time and space can interchange to the point that time can have a theoretic start point. In any case, there is absolutely no way to know if, let alone what, happened "before" the big bang. In fact that idea may be a misunderstanding of what time is.
As one explores these questions, at least knowing some of the current ideas in physics is useful, though not necessariy truth with a big T.