"Bodies will continue to move with a uniform velocity (which includes being stationary) unless acted on by a resultant force."
This means that if a body changes speed or direction a resultant force must be acting on it.
"Resultant force is equal to the rate of change of momentum."
This forms the basis of Newton's equation, F=ma. This equation actually comes from the idea of momentum, which can be found in the Principles of the conservation of momentum Learn-it.
The direction of the acceleration is always in the same direction as the unbalanced force.
"Every force has an equal and opposite force acting on another object."
This can all sound difficult to understand, but let's look at the laws in a simple example.
Putting all three laws together: