To check the polar alignment of your telescope look trough the polar scope. When turning the Ra axis the polar star should move in the exact circle in the eyepiece without any deviation. From the Go To control panel, you can check the polar accuracy after alining the telescope by going to align – > display polar alignment. The deviation should be not more then a few minutes. You can use the menu option to correct the alignment. The telescope will point a star and then you will have to center it in the field of view by moving only the azimuth and altitude axis.
So in short : align -> polar align, you can use the the procedure for precise polar alignment. The telescope will first point the last object in the field. You will need to center it with the controls. Then the scope will point again and you will need to center the object again but this time using the azimuth and latitude axises of the head. when done the RA mount axises will point at the celestial pole and star trails during long exposures will be reduced.

Good alignment is critical for long exposure photography. Good luck!