Abhishek Kumar

NO.

In some ways, it is the other way around. Newton’s first law of motion is the special case of the second law.

Newton second law of motion says that force is the rate of momentum.

F=dp/dt=mdv/dt.F=dp/dt=m.dv/dt

When the external force F=0, we get, dv/dt=0 dv/dt=0, which suggests that velocity is constant.

It is the actual statement of Newton’s first law of motion: In the absence of net external force, an object in rest remains in rest, and an object in motion stays in motion with shape speed in the same direction, or different word velocity remains the same.

The speed of light is fixed because it makes the laws of physics well behaved no matter how you move relative to any frame of reference.
Or more precisely, special relativity makes the laws of physics invariant under the Lorentz transformation (actually the first of Einstein's postulates of special relativity. The other being c=constant in any frame of reference).

The position vector of a particle is defined as the vector starting from the origin to the point where the particle is.

The displacement vector of a particle is defined as the vector joining its initial position to its final position.

In other words, the displacement vector is a change in position vector.