28 Degrees by GE Money is one of the best rated travel cards. It has no fees for currency conversion, deposit or ATM withdrawals. It has an instant application process and mine was delivered within 72 hours.
Credit cards are a great way to improve your credit rating.
I was recommended to take out two (different) credit cards to ensure you are gathering ratings at two different agencies (Citibank has two cards that are with two agencies). This is patently BS, as all three credit agencies share all of their data with each other. You must have a Social Security Number (SSN) to get a card and without a credit rating you will have to deposit money into the accounts like a prepaid credit card. you will have to get a "secured" credit card - secured agains a term deposit with your bank. It is not "reloadable" like a prepaid credit card.