Albert Barnes Commentary Luke 5:10

"and so were also James and John, sons of Zebedee, who were partners with Simon. And Jesus said unto Simon, Fear not; from henceforth thou shalt catch men." — Luke 5:10 (ASV)

Fear not. He calmed their fears. With mildness and tenderness he stilled all their troubled feelings, and to their surprise announced that from now on they would be appointed as heralds of salvation.

From henceforth. Hereafter.

Shalt catch men. You will be a minister of the gospel, and your work will be to win people to the truth so that they may be saved.