The first sentence is sloppy.
This is incorrect. I could believe13.8 billion years ago, all the matter and energy contained within our Universe was concentrated into a volume of space about the size of a soccer ball.
From a finite thing only a finite thing can grow according to GR. The universe as a whole seems to be infinite by observation. The expansion of the whole universe has to be from an infinite prior state.13.8 billion years ago, all the matter and energy contained within our OBSERVABLE Universe was concentrated into a volume of space about the size of a soccer ball.