Had Jesus formally been given authority to preach in the synagogue? At Luke 4:16-17 we read:

" When he came to Nazareth, where he had been brought up, he went to the synagogue on the sabbath day, as was his custom. He stood up to read, and the scroll of the prophet Isaiah was given to him...."

I would like to know what the relevance of a synagogue in day-to-day life of an average Jew was;  and whether Jesus had  formally been given authority to preach in the synagogue. What does the Catholic  tell us on the subject ?
From the commentary on St. Luke 4:16 by Conelius à Lapide, S.J.:


  And stood up for to read. It was (and still is) the custom among the Jews that each one should read the Hebrew books of Holy Scripture in the synagogue on the Sabbath-day, both that he might learn the law of God from it, and also that he might be stirred up to the worship, love, and service of God. Moreover, it was the part of the Rabbin and the teachers, such as Jesus was, to read the Holy Scripture publicly, to interpret it, to preach, and to teach.


St. Ambrose commentates (recorded in St. Thomas Aquinas's Catena Aurea on Luke 4):


  The Lord in every thing so humbled Himself to obedience, that He did not despise even the office of a reader, as it follows, And he rose up to read, and there was delivered to him the book, &amp;c.


Quite amazing! As Origen says:


  He opens not the book by chance, and finds a chapter containing a prophecy of Himself, but by the providence of God.