Question

where to use have had ?

Answer 1

see these sentences :-
I have my pencil. 
I have my phone


I had taken lunch
I had seen

Answer 2

Have: to show possession of something in present tense. for plural nouns and pronouns.
Like ....... I have the bag u had given me.
Had: past tense of have and had. used for both plural and singular nouns and pronouns.
Like...........I had the bag u had given me.
 :)