Answer 1

What Kepler's constant ? ? ! ?

The only constant in Kepler's laws is in the third one, where it says something to the
effect that (square of a body's period) / (cube of its distance from the central body)
is a constant.

That means it's a constant for multiple little ones orbiting the same central body.
But it's not the same constant for other central bodies.

It's one constant for the planets, asteroids, and comets orbiting the sun.

It's a different constant for the moon, TV satellites, weather satellites,
and military satellites orbiting the Earth.