Let's teach you how to fish !wavewavewavewavewavewavewavewavewavewavewavewavewavewavewavewavewavewavewavewavewavewavewavewavewave

You should first choose a place to settle down. Use the directional arrows of your keyboard,  or just click somewhere on the shore to move your player. 

Once your player is correctly positioned, use the enter/space key or click on Fish here ? to prepare your throw.