This page contains various arrangements of instruments for practice. When you first start playing the berimbau, the best part to learn first is the medio part (so you can play along with the main gunga part).
Here is how both parts look:

In this video, both the gunga and medio are playing.
To accompany this, you would play the viola part. This is also a good track to practice your singing!
In this video, just the gunga is playing. Here’s what the gunga part looks like:

To accompany this, you would play the medio part.
In this video, just the medio is playing. Here’s what the medio part looks like:

To accompany this, you would play the gunga part.