We will have the following:
Newton's first law: If a body is in motion it will remain in motion and if a body is still it will remain still until an external force acts upon it.
The example would be if Usain is still at the beginning of the race, he will remain still until he uses enough force to move.
Newton's second law: F = m*a
The example would be that in order to move his own mass he will need to apply enough force so he can start running, and the change in velocity he will experience will then be greater than 0.
Newton's third law: Every action has an equal and opposite reaction.
The example would be when Usain is running he is pushing the Earth so he gains movement, and so the Earth pushes Usain with the same magnitude but in opposite direction.