To shoot for goal, use your pickaxe or slide to hit the ball. It's even possible to do a volley (midair shot) to goal. Pass to open teammates too.
Goalkeepers are the only players with a hammer. To make a diving save, hold the "BLOCK" button, move to the left or right and press "JUMP".
Dribbling is done by running (tactical sprint recommended) to the ball and making sure it hits your feet. Don't waste stamina, it regenerates slower.