So, you fell for a Brazilian (Latino? Englishman? South African?) ?
Here, you'll find useful information about how to apply for and go through with a K-1 fiance visa to the United States.
1. So you fell in love with a Brazilian - Big Step 1: The I-129F Package
2. So you applied for a visa - Sending off your application, the Big Wait, and the NOA-1 and 2
3. So you got an interview - Big Step 2: Preparing your visa interview package
4. So you're thinking about emigration - things to consider before you start the process (prequel)
5. So you're off to the consulate - the visa interview and what to expect