“I’m going out to fish,” Simon Peter told them, and they said, “We’ll go with you.” So they went out and got into the boat, but that night they caught nothing.
John 21:3 NIV

I don’t think I see anything wrong with Peter and the others going fishing. At the time they knew Jesus had come back but he wasn’t with them. So it makes sense to do what you know. Perhaps Peter wanted to do what helped him feel grounded. Fishing was something that was natural to him. So while waiting for the what next we do what is nstural to us. When Jesus showed up Peter gave up what he knew and ran to Jesus.

He said, “Throw your net on the right side of the boat and you will find some.” When they did, they were unable to haul the net in because of the large number of fish.
John 21:6 NIV

So Jesus shows up and provides from them again. Just like he called Andrew and Peter in the beginning of His minisrty He gave them a catch the provided for them and their families. Now he is calling them to the next level of ministry. Their mission. So he provides again.

Jesus said to them, “Bring some of the fish you have just caught.”
John 21:10 NIV

Jesus already had fish on the fire but he also had them bring some of the fish they caught by His grace. Is that not exactly how it is in minisrty. God calls us. He prepares us and provides for us. He places people and things in our lives and path but we have to take what he gives us and use it. We must respond. We still have to do of the work.

So bring the fish that He has provided you and lay it down before him and hear what He would have you do. Feed His Lambs, take care of His sheep, feed His sheep.