Whenever you’re by water in Red Dead Redemption 2 you can pull out your fishing rod and cast a line. You can equip the fishing rod by opening the weapon wheel with the LB/L1 button and then tabbing to items with the RB/R1 button. Once you’ve got the rod equipped you’re going to need to know the basics for fishing.
You can put bait on your hook by using the LB/L1 button when you have the rod equipped. Or you can press Y/Triangle to quickly equip bait. Once you’ve got the line baited, you can press LT/L2 to grip the rod and then press RT/R2 to cast the line.
Now that the line is in the water you’ve got some moves you can do. You can move the rod with the Left Stick and use the Right Stick to reel the rod in if you move it in a clockwise circular motion. You can flick the fishing rod with attract fish to the lure/bait.
Once you feel a nibble on the bait/lure, you can hook a fish by pressing the RT/R2 button.
After you’ve got a fish hooked you’re going to need to reel them in with the Right Stick. Sometimes fish will struggle once you’ve got them hooked. If a fish is struggling it could possibly break the line. Control the fishing rod by holding the Right Stick in any direction to prevent the fish from doing so.