Hi Haasler,
Here you can find guidelines, including description of the keys: https://www.youtube.com/watch?v=JgRC736jPBU
On a desktop (Windows or Mac) you can use WSAD or arrows for movements and mouse for selecting target of your kick or pass. You can make pass by clicking left mouse button and selecting target player. To kick to a point in the field, right-click that point. To make a shot to the gate, push right button of the mouse, choose a sector of the gate, and release the button.
To make a one-touch-kick choose your target by right mouse button before you got the ball. Once you receive a pass from your teammate, the kick will be done automatically to the target you chosen.
To attack your opponent and make a tackle, use left mouse button.
Use mouse wheel to zoom-in and zoom-out. Press spacebar to activate your super-power.
On a mobile the controls are shown on the screen: stick on the left is for running, three buttons on the right is for pass/tackle, kick, and super-power. You can zoom in-out by pitching in the top of the screen.
All the above is about “Pro” mode. In Casual mode controls are simpler but they give you less control over the ball.