Question

Earth rotates round the sun and the axis doesn't change. When the Earth moves how does the pole star remain in the axis of the Earth.

Answer 1

If you project a line through the earth's rotational axis and out into space it will eventually pass close to Polaris, the pole star.
The earth's axis always tilts in the same direction while it orbits around the sun. Only a phenomena called the precession of the equinoxes changes the direction of the earth's axis but that takes 25,000 years to complete a full cycle.
All stars are moving round the galaxy. Most are moving at different speeds from our sun, and sometimes also in different directions. But space is so vast that in historic time we see very little such motion.
That's why the Pole star appears stationary.