Why Polaris doesn't move?

Polaris is just so far away that its motion is impossible to see with our eyes.

The distance to Polaris is 434 light years.  That's 27.4 million AU, where an AU is the distance from the sun to the earth.  So the motion of the earth around the sun over a year causes an incredibly small shift in the apparent location of Polaris.  That angle is 2/27,400,000 radians = 0.0000042 degrees. 

Next, you mentioned the motion of the sun.  The sun moves more in a year than the distance between the earth and the sun.  The sun is travelling at about 108,000 km/hour, so in a year, it moves about 6.3 AU.  The apparent movement of Polaris due to our being carried along by the sun (orbiting the center of the galaxy) is 6.3/27,400,000 radians = 0.000013 degrees. 

But Polaris is also moving around the center of the galaxy and moving very approximately at the same speed and direction as the sun, so the actual angle change on the sky will be even less than the above number. 

The rotation axis of the earth essentially does not change as the earth goes around the sun each year.  It points to the same spot on the sky, which is very close to Polaris.  The earth's spin axis does move over thousands of years, but the movement from year to year is too small for us to notice without telescopes.

 https://www.quora.com/Why-doesnt-Polaris-the-Pole-Star-move-if-Earth-is-revolving-around-the-sun-and-the-sun-is-also-revolving-around-the-center-of-the-galaxy