I want a buy a new iphone to go to Brazil. I want unlocked iphone. But I dont know how to buy it. can you help me out?

1. Purchase Apple Products from the Apple Online Store, Apple Retail Stores, and many Apple-authorized resellers and wireless service providers.
2. If you choose "Connect to a carrier later" (Unlocked iPhone) when you buy your iPhone, you can activate your service when you receive your device. Then you can use any SIM globally. However...

IMPORTANT RESTRICTION FOR iPHONE, iPAD, APPLE TV AND HOMEPOD SERVICE.

Apple may restrict warranty service for iPhone, iPad, Apple TV and HomePod to the country where Apple or its Authorized Distributors originally sold the device.