so, you are on switch so it would be Y i assume to move the green bar. you move it up and down by pressing down on Y. Pressing makes the bar go Up and relaasing makes the bar go Down. you want the green bar on the fish, which makes the bar on the right go up. when the progress bar reaches the top you get your fish. if you need to, you can buy the training rod from Willy's for 75 gold. that helps, but you can only catch common fish.