new player worried about quest (bug?)

HI, I am very worried. someone asked in general chat about completing the same quest twice, and i said that i had done that before as well. and about 5 people said i was reported and would be banned.
I never played wow before and had no idea this was a bug i assumed it was normal for some quests. and now I am not even sure how to make a bug report. the post on the subject is very confusing.
can anyone please help me? did i break the rules? it was a quest started by a looted item..
I never played wow before and had no idea this was a bug i assumed it was normal for some quests. and now I am not even sure how to make a bug report. the post on the subject is very confusing.
can anyone please help me? did i break the rules? it was a quest started by a looted item..