can i go visit hong Kong by chinese visa ?

Dear sir or mam .
My name is fazal Ahmad Anis from kandahar Afghanistan.
I have 3 questions. Kindly answer it.

1: I am an afghan passport holder how can I get china visitor entry permit?
2: when I get it can i visit hong Kong and macao by Chinese entry permit?
3: what is china visitor entry permit payment ? In usd.