An introductory paragraph on the accidental discovery of Brazil by European navigators may be an attention-getting beginning.
The discovery was accidental because the ship actually was intending to follow the African coast down to the Cape of Good Hope and then on to India. But there is a calm area about halfway down the West African coastline. The Portuguese knew about the calm area and would sail westward to avoid it and then back eastward once it had been passed.
It is thought that Pedro Álvares Cabral (c. 1467/1468 - c. 1520) accidentally went too far westward, and that is why he landed in northeastern Brazil on April 22, 1500. The ships departed May 2-3 and managed to get back on track for rounding the Cape off present-day South Africa. Unfortunately, the delay headed the ships at a later time through the Cape, and so Bartolomeu Dias (c. 1451 - May 29, 1500), who was the first European known to reach the Cape in 1488, and 389 others were lost in the seasonal storms.
This beginning allows you to use the early connections between African and continental Portuguese cultures that found such a unique expression in their interactions with the native populations of the Northeast.