Its really just trial n error, Bill=Shipping etc. As for giftcards those sites are always pretty secure and will require KYC... Random drop-shipping stores and shit like that usually pretty easy. Be careful just punching info in because you will instant kill cards / get banned by payment...
Trash website. I repeat do not send money to this site. I sent money to the site and bought a credit card number and it didn't work. I submitted a ticket for a refund and no answer.