Rabbis Hillel and Shammai did not earn their living by teaching. They were laborers, just as others around them were, and that is how they put food on their tables. Being a rabbi at that time did not have attached to it monetary rewards, except for those who were in charge of the temple at Jerusalem. Even St. Paul earned his living as a tentmaker, not as a teacher.
Joseph, the man whom God made responsible for Jesus' upbringing, would have done his job as a conservative Jewish husband and father. When Jesus was 3 years old he would have started the study of Torah, including memorizing passages of Scripture, and even entire books (it was not uncommon for students to do this). If he began his studies in the orthodox tradition, the first book he would have studied would not have been the one we call Genesis; it would have been the one we call Leviticus.
At the age of 10 Joseph would have started teaching Jesus a trade. Being identified as a carpenter required not only a skill in wood, but also a skill in stone. Jesus would have learned how to take both wood and stone and put them together in such a fashion as to build a structure that would stand firm against the elements. Remember his teaching his disciples about building a house upon bedrock versus building that same house upon sand? This was Joseph's teaching revealed.
I agree with others on this thread that Jesus was already well-known to the apostles before he called them. I myself believe that he had already been teaching in that region for approximately 3 years before he approached them. But he had also continued putting food on the table for his family through his performing the work which Joseph had taught him. There were probably some, such as Nathanael, who hadn't heard of him, but the core of the apostleship (Peter, James and John) had in all likelihood known him for some time.