Nobody currently alive was around at the time of the Big Bang, so far as we know. So we go to science with the scientists we have.
Fortunately, those include Caltech cosmologist and theoretical physicist Sean Carroll... he's got the science chops PLUS the Ted-talk friendly manner to communicate what he's learned.
Which he puts on paper in a new book called The Big Picture: On the Origins of Life, Meaning, and the Universe Itself. So get ready for a discussion that will expand your mind... or at least your concept of the universe and how we all got here.