Article in English: Tap the Netflix app icon, which resembles a red "N" on a black background. It's a red button at the bottom of the screen. If Netflix is logged into a different account, first tap ☰ and tap Sign Out (you may have to scroll down) to log out of the account, then tap the Sign Up link on the main page. This will take you to a page with a list of plans. Since you aren't paying for the first month either way, it's best to leave the default top-tier plan—which allows HD streaming—selected. If you do plan on paying for subsequent months, you may want to select a cheaper plan. It's at the bottom of the screen. This will take you to the account creation page. Type a working email address into the top text box, then enter the password you want to use for your Netflix account into the bottom text box. It's at the bottom of the screen. Tap one of the available payment methods, which usually include credit (or debit) card and PayPal. On an iPhone, you'll tap SUBSCRIBE WITH ITUNES here. If you're using a card, you'll type in the card's number, name, expiration date, and security code; PayPal users will log into PayPal and follow the on-screen instructions to confirm the payment.  On an iPhone, you'll enter your Apple ID or Touch ID to confirm your iTunes subscription. After this point, your membership is active. Even though you aren't paying for your first month, Netflix requires a payment method to set up your account. It's at the bottom of the screen. This will start your Netflix membership; you can use Netflix for free for one month. In order to enjoy your full month of Netflix without having to pay for any additional months, you can cancel your membership a few days before the renewal period. You'll need to use a computer to do this:  Go to https://www.netflix.com/ and sign in. Select your account if necessary. Hover over your profile icon in the top-right corner, then click Account in the drop-down menu. Click Cancel Membership in the top-left corner of the page. Click Finish Cancellation in the upper-left side.

Summary in Vietnamese:
Mở Netflix. Chạm vào nút JOIN FREE FOR A MONTH. Bấm vào SEE THE PLANS. Chọn một gói dịch vụ. Bấm vào nút CONTINUE. Bấm vào nút CONTINUE. Điền địa chỉ email và mật khẩu. Bấm vào nút CONTINUE. Chọn phương thức thanh toán. Điền thông tin chi tiết. Bấm vào START MEMBERSHIP. Huỷ tài khoản trước khi bạn bị tính phí.