You need a visa for Zambia if you have a Brazilian passport

The KAZA UNIVISA is for travellers visiting Zambia and Zimbabwe for tourism during one trip. You can travel freely between these two countries, entering and exiting each country multiple times. Travellers must start your trip in Zambia if they apply through the Zambian government. The visa becomes invalid if you travel outside of these countries. An eVisa is the fastest and easiest way of obtaining a visa as you can submit an application and supporting documents online. If approved, you'll receive your eVisa confirmation electronically. When you arrive at immigration, you will be asked for your passport and eVisa to ensure you have proper documentation. Entry to Zambia with a KAZA UNIVISA is supported at 2 airports, and 2 land borders. See the government site for more details.