Dear Designer,
We would like to emphasize that the cover is supposed to face towards outside the house for people walk by to see. That means it's better to show on the cover something happening inside the house. For example, if you are drawing a witch, the background behind the witch is better to be something inside the witch's castle rather than the trees or the moon. In some other good door cover designs we saw, they show monsters trying to breakout from the house or creepy eyes staring at the walkers on the street.
Thank you very much~

Should it be realistic(3d render) or illustration.

No, it does not have to be 3d rendering.

Could you please check my submission and feedback please?
Thanks