Apple Music debit only $1 of my Credit Card (twice)

Hi,

I wanna try Apple Music, but when I submited to 3-month trial, says my account doesn't have founds, when I try to use my credit card on iTunes Store, says the information of my credit card doesn't is the same on my bank, and of course, my credit card is from Brazil, and my Apple acount is american, but it's international credit card.

And then I can't use Apple Music. Ok, no problem, I should wait it come to Brazil, and transfer my american account to be a brazilian account. But they made 2 debits on my credit card, with one of only $1, why?

I think it's 2 debits because I tried 2 times on iTunes Store to use this credit card. But why the debit?