So my square selection is circle ss: https://photos.app.goo.gl/1q5p4hgVLNt9rq1XA.
And is it possible to disable this "shadow" when i move selected object (sometimes its hard to aim perfectly) ss: https://photos.app.goo.gl/6MufGupjhdQ2MbUN9
PLEASE HELP

In your first screenshot, that looks like a solid ellipse and not the dotted outline of a selection.
Do all your selections look like that?
What happens if you use the elliptical election tool?
What do you see if you toggle the Display Mode icon (far left of the status bar at the bottom of the screen) from Ants to Mask?

In the second screenshot, that is an artifact of the Tranform tool constructed image that goes away when you finalise the transform.
You can get rid of it by turning off canvas graphics acceleration in Settings -> Configure Krita -> Display -> Canvas Acceleration tab.
Or, you can use the Move tool for moving because it doesn't have that artifact.

I figured out the first problem by myself. But with the second one you really helped me>
Thank you (: