Can some one pls tell how to

remove preview text from viewport and rendering

That should be gone once you’ve builded your lightning

But whenver i build lighting …the 3d object that imported will look like shaggy…how to fix that ??

what do you mean by shaggy?

You can also simply set your directional light from stationary to movable. Would be a temporary solution until you learn lighting. Keep in mind movable lights are computationally more expensive than static or stationary lights, so it is unideal to ship a game with the directional light set to movable.