Newton's first law:
     a body, in the absence of external forces:

• remains at rest if its initial velocity is zero
• moves uniformly, that is, at a constant velocity, if its initial velocity is different from zero.
  

While the first statement is obvious, the second one is not so evident. The following images try to explain them.

• If it is at rest and no forces act on it, it will remain at rest.

• If no forces act on it, but it was moving, it will continue to have a uniform movement, (observe that the velocity does not change in value, direction or  orientation).