The Antichrist or son of perdition doctrine comes from 2 Thessalonians 2:3-4
"3 Let no man deceive you by any means: for that day shall not come, except there come a
falling away first, and that man of sin be revealed, the son of perdition;
4 Who opposeth and exalteth himself above all that is called God, or that is worshipped; so that he as
God sitteth in the temple of God, shewing himself that he is God."
To get a better understanding I suggest you read commentaries from some of the great theologians of centuries past
that I've come to trust such as Ellicott, Barnes and Meyers.
All of their commentaries for the above verses (and every other verse in the Holy Bible)
can be found on this BibleHub page here.