When you have a fishing rod, select it in the shortcut bar and right-click to throw the fishing line into the water.

Keep an eye on the float. After a while, you can see a small splash around the float. When a fish wants to bite a hook, it will have a trajectory to float. If Particle Effect in Video Settings is set to Minimum, you won't see the track.

When the float is submerged, immediately right-click again to retract the fishing line. When the fish bites the hook, it takes about half a second to close the rod. If the fish runs away, the line can stay in the water and wait for the next bite.

Successfully closing the pole will make a fish or other object fly to the player in the air. Under normal circumstances, it will fly directly to the player, but if there is a square in the middle, it may bounce at an angle.

Successful fishing will also produce an experience ball of 1-6 experience at the player's fishing position.

I hope the above information can help you solve the problem. Please feel free to let me know if you have any other questions.