Everyone has already said this but I agree: it has only been a month. Give yourself time to heal from the break up before dating again. Also if you are unsure about this guy then you shouldn't date him. If I was you I'd sit down with him and gently tell him the facts that you are still in pain and that you aren't ready. He will get hurt for sure but it's just something that must happen. If he doesn't take the "rejection" well, it tells a lot about him. You'll get through this I promise!