Judas Iscariot, the son of Simon (apparently not the son of any of the other persons named Simon mentioned in the Gospels) is always listed last on each list. That also was not accidental. He is not worthy to be mentioned along with the rest. He gave up his portion unrepentant. He was known as Iscariot, which may refer to his hometown, which is also listed as Kerioth, a variation of Iscariot. The arguments as to his identity are still (and will remain) open to the providers of speculative theories.
One name appears listed differently in some of the lists. Thaddeus is called Judas (or Jude) and is listed as the son of James who was a son of a man named Alphaeus. Levi (known as Matthew) is also listed in Mark 2:14 as a son of Alphaeus, which would mean that he was the brother of James and an uncle to Thaddeus. To confuse things Matthew and James are nowhere listed together and are not noted as being kin in any other place. But I suggest that Mark did not get it wrong as the writer was too close to the participants and proceedings to miss such a detail. Then what should be obvious is that there are groups of blood relatives among the twelve: Peter and Andrew, James and John, all brothers, along with Matthew and James, and James’ son Thaddeus (or Jude).
Some had nicknames or titles (the sons of thunder, and as mentioned, Simon the Zealot or “the Canaanite”). All of these designations had significance. I suppose that the sons of Zebedee were called sons of thunder for a reason. We could speculate and try to identify why they were given this nickname, but the title certainly had to fit the titled. And so we might imagine that their father was a man with a considerable set of vocal cords or that they themselves were fully piped and needed no assist to be heard. Possibly that when riled or stirred up could be heard in their displeasure or by their response and in their zeal. Whatever may have been the case, it is beyond the information that is available.
Simon was called both a Canaanite (likely meaning that he hailed from the region of Canaan) and a “zealot.” The zealots were a Jewish national party sworn to assassinate every Roman or Jewish sympathizers who were considered traitors to Rome. I would understand that to mean that this Simon now a disciple and apostle was a former zealot and was known for his previous affiliation, but such behaviors and politics would never be tolerated by the Lord. He certainly was not both an assassin and apostle.
Matthew (Levi) the tax collector was not in a position of merit. A full third were fishermen: Peter, his brother Andrew, and also James and his brother John. Of the remainder we know nothing of their occupations, their work or families. Most of them were from Bethsaida, including Philip (John 1:44), or from Capernaum and the surrounding region. We know that Thomas likely had a twin as he was also known as Didymus, which is the Greek word for twin (John 20:24).