Hi Brother :)
I was taking look on site and saw your question :)
Let Me Help You :)
Firstly, to use 'Past Perfect', there must be at least 2 events in past. For example;
''I bought a new car. ''
There is just one event. Right? Only event in past : Bought a car.
But , to use past perfect there must be 2 events.
For Example :
I went to Brazil After I had gone Turkey
Look. There are 2 events in past. To go Brazil, and To Go Turkey.
Both of this 2 events occured in past. Right?
You must use ''past perfect'' for first event. And ''simple past'' for second event.
For Example :
Firstly I ate a hamburger. Then I ate a pizza.
There are 2 events right, Brother? Yes. Which one is first? ''To eat hamburger.''
So when we say it, we must use past perfect
I had eaten a hamburger. Then I ate a pizza''
Notice:
You cant use ''past perfect'' 2 times in one sentence.
I had gone Brazil Before I had Gone Turkey (X) (FALSE)
I HAD GONE BRAZIL BEFORE I WENT TURKEY (V) (TRUE)
In 2 events in past, you must use ''past perfect '' in first event. :)
I hope I could Help You, Brother :)
Love From Turkey :)