"How could God have used a point in time to start creation."
Humans use time to point to this event that or the other. The term a point in time is just a human reference to when God may have done a certain thing - our entire being is based on time - our daily lives are based on time - so we have a tendency to use time as a reference.
Why didn't the universe always exist - there is one scientist who claims there was a universe before this one
There was a universe before ours, says Nobel laureate Roger Penrose: Report
There are those who said the universe had no beginning - it existed before the Big bang singularity
The universe has no beginning: physicists refute the Big Bang theory
Who can say that there isn't more than one universe (there are three heavens spoken of by Paul) in this infinite space. Universes created by God prior to this one. Man can only observe 400 billion plus light years away, past that he can't see anything (so they say)
What's written in Scripture is written for man, for earthlings.