Before opening a credit card account, take a look at the pros and cons at NerdWallet and compare credit cards. (Make sure there is no annual fee)
Note: If you plan to travel abroad find one that doesn't charge additional transaction fees when using the card in a different country - the fees are usually around 3%.
Amazon Rewards Card through Chase card gives 3% rewards on Amazon purchases (2% and 1% on other items) and no international transaction fees. Sign up through Amazon and get a $50 gift card upon credit approval.