Support how to remove elements from specific category

[orospu]

hello
i saw code before here but now cant find
so basically i have main forum and subforums and members cant post in main forum before they choose one subforum
but when members click main forum there say "you must log in or register to post here" but they dont have access to post here so i dont need this information text
also i dont share anything in main forum so i dont need forum list too
how i can remove these? i added image below bcs of i think my english bad and didnt explained
note: i need to remove these from specific category not all!

 

[</clown>]

attach image