I have a few questions about breeding.

I just have a few questions about breeding, since all i really know is sticking a ditto and a pokemon in daycare makes a egg.

1. I have not play black or white, I just skip'ed to black 2. When do you get access to the daycare?
2. I tried for the dream world for the first time today and got a aron with heavy metal and head smash. Is there a way with breeding i can get the ability rock head instead and keep head smash. (since far as i know it's the best recoil attack) and if so how? Thank you for your time.