can I help translate the mod into Brazilian Portuguese?

You can!

1. Fork the project.
2. Clone your fork to your computer
3. You will need make language files matching the existing en_us.lang files in each mod and content pack resource location.
   For example:
   https://github.com/FlansMods/FlansMod/tree/1.12.2/src/main/resources/assets/flansmod/lang
   https://github.com/FlansMods/FlansMod/tree/1.12.2/src/main/resources/assets/flansmodapocalypse/lang
   https://github.com/FlansMods/FlansMod/tree/1.12.2/run/Flan/Apocalypse%20Pack/assets/flansmod/lang
4. Commit and Push your changes to your fork
5. Open a Pull Request detailing your changes

thanks