What did Andrew do before he was a disciple?

He was a fisherman, as were Thomas, Nathanael, James, John, and possibly Andrew and Philip.

John 21
1 After these things Jesus shewed himself again to the disciples at the sea of Tiberias; and on this wise shewed he himself.
2 There were together Simon Peter, and Thomas called Didymus, and Nathanael of Cana in Galilee, and the sons of Zebedee [that is, James and John] and two other of his disciples.
3 Simon Peter saith unto them, I go a fishing. They say unto him, We also go with thee. They went forth, and entered into a ship immediately; and that night they caught nothing.

J


A.T. Robertson in "Word Pictures in the New Testament" says on John 21:2 that:-

...These seven (Peter, Thomas, Nathanael, the sons of Zebedee, and two others). We know that the sons of Zebedee were James and John (Mat_4:21), mentioned by name nowhere in John’s Gospel, apparently because John is the author. We do not know who the “two others of his disciples” were, possibly Andrew and Philip.

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