Work through Customizing activities in the Implementation Guide (IMG). The following areas are relevant to Brazil:

The above links merely provide a list of all required Customizing activities, along with how to navigate to them. Detailed descriptions of the integration into Brazilian business processes and compliance with legal requirements are provided in documentation of the application areas that follow. In addition, you should refer to the IMG documentation for instructions and notes pertaining to the activities.

Upload tax rates for your tax codes.

Maintain the conditions for tax calculation in SD.

Make additional Customizing settings needed for processing returns, complementars, and corrections with batch.