Cuate:
As you noted the four gospels of the New Testament mention very little about Jesus’ early years.
There is a brief account of the events surrounding His birth. Then a gap till He is 12 years old, when mention is made of His visit to the Temple in Jerusalem. Then another gap until He begins His ministry at about 30 years old.
There are, as you suspect, sources of information which are not part of the sacred canon. They are of varying degrees of reliability. Then there is a great deal of commentary-type material based on analysis of what little actually appears in the New Testament and even on pure speculation. This, too, varies widely in dependability.
I’ll be glad to offer my understanding of this time in His life. But bear in mind that I don’t speak with any great authority. So take it or leave it, as you will. I’m just trying to answer your questions.
I think you are correct in noting that the people of that time married a bit younger than they do today. It was not uncommon to get married between 14 and 20 years old. But I don’t think that everyone got married between those ages, or even at all necessarily. A young man had to be able to support a wife and family in order to be eligible to consider marriage. Thus quite a few poor guys may have had to forego ever getting married. Likewise, rich guys could have several wives. So Jesus staying single the whole time would not have appeared too unusual.
Joseph had his own carpentry shop, and so was somewhat successful. Mary was not Joseph’s first wife. Joseph was a widower about 30 years old with several children from his first wife, when he became engaged to Mary. Mary was about 15 years old and had never married before. So after their marriage, Mary had to deal with several step-children who resented her, some of whom were not much younger than she was. They also resented Jesus, their half-brother, because He could be another claimant on their father’s property.
Joseph was still alive at the time of Jesus’ visit to the Temple in Jerusalem but, as you noted, is not mentioned at the time of Jesus’ ministry. Joseph died sometime between those two events. Then without Joseph to protect them, Mary and Jesus were put out of Joseph’s house by the children of the first wife. They felt they owed nothing to Mary, and they wanted to get rid of Jesus before He became old enough to claim part of the inheritance.
So from the time of Joseph’s death until Jesus began His ministry, He had to work to support Himself and his mother. The two of them probably led a meager existence without the backing of the carpentry shop. During the three and a half years of Jesus’ ministry, Mary stayed with other relatives – probably her cousin Elizabeth, mother of John the Baptist. At the crucifixion, Jesus entrusted John the Beloved to care for his mother during her remaining years.
As an interesting side note: One of Jesus’ half-brothers who had helped put Him out of Joseph’s house when Jesus was young, became convinced of Jesus’ divinity after the Crucifixion. He then became a preacher for the early Christian church and even wrote a book that became part of the sacred canon – Jude.