Since it is a brand new bike are the wheels new? If the spokes are not properly tensioned you will hear a ping/pop as they settle in, kind of like guitar strings when you put new ones on the ol' axe.

My favorite "pop" theory though is the ungreased pedal thread. This will make the most awful/scary sound sometimes if the threads are not greased. Also check your chainring bolts to make sure they are on tight.