my dads been gone for a month and he wants to come back. is it bad that i kinda do not want him to?

There's a variety of things his departure may've brought to your household that you've become accustomed to. One is that maybe there's no fighting or anger in the house. Another might be that he hurt you so much that you don't want him back in your life, at least not with him living there. His departure has hurt multiple people, you included, and it's natural that you would have your own thoughts and feelings on the matter, and there's no specific reason why you have to want him back, so you shouldn't feel guilty if you don't. You're entitled to your own feelings and thoughts, no different to anyone else.

I don't think it's bad, it's how you feel. Maybe you can ask yourself why you feel that way. From my own experience I know I felt letting my father come back into my life told him it was okay that he left. I needed him to understand that I was deeply hurt by him leaving and one way of communicating that was to not let him back into my life. Eventually, with help of counselors and friends I was able to tell him how I felt with my words and help him understand that it was uncomfortable for me if he would come back home like nothing happened. I don't know your situation, but I do know it is fine to feel you don't want him to come back (yet).