So with Paul s text. Do not try to guess what is second unless you look at the context. The dead in Christ will rise first. He is talking about dead saints and live saints. He is saying that before the live saints are caught up in the clouds, the dead saints will first be raised.
Nothing whatsoever is said about two resurrections.
He spoke of the condition of two groups. However, these two resurrections will take place at the same time. A better explanation seems to be found in New Testament first principles. See also Romans 6. For the Christian, this is the first resurrection.