Welcome to Android Central! The 2G and 3G network bands it supports are listed here:
ONTOP Nugget D5 (Android, 4 GB, WiFi, Dual Sim, Black) price, review and buy in UAE, Dubai, Abu Dhabi | Souq.com. It apparently does not have LTE. What Brazilian carrier do you plan on using? Compare its network bands with the supported bands on the phone. If there is overlap, then the phone ought to work. Not sure if WhatsApp is compatible, though--you'd just have to try installing it.
Also, be aware that it only has 4 GB of internal storage, which means that after accounting for the OS, you'd only have about 1 GB or less to install apps in. That can fill up very quickly, and a microSD card wouldn't do much to increase how many apps you can install.