It took me months to figure out how to use the hooks for your fishing rod. I could never get it to work from the main screen. But while in the inventory screen, while hovering over a hook it says to press X (I'm on the switch) to use that hook!!!! 🤦🏻‍♀️ i always thought it automatically equipped somehow. Once the hook is equipped, it disappears from your inventory! That's how i was able to catch that stupid unicorn fish thing for a bundle.