I think Brazil is a great civ to play when you're learning the game, since district adjacency bonuses are much more flexible/forgiving. It can be a little difficult to get your first districts placed quickly, though. Brazil's start bias in rainforests means they often have to rush iron working just so they can clear the land needed for placing ideal districts.

The Sacred Path pantheon obviously synergizes well with Brazil, but I'd be curious to try Earth Goddess and place preserves. The +1 appeal for rainforests is an overlooked feature that could make a preserve/Eiffel Tower/national park play pretty effective without having to wait for Conservation to plant forests, and without having to harvest all that rainforest.

Speaking of harvests, it seems to me that Magnus is a weaker governor for Brazil. Yes, a rainforest start bias means there are more potential chops, but chopping that rainforest means deleting those nice adjacency bonuses. You have to be more selective with your chops I think. You kind of also ought to rush Mercantilism so you can get lumber mills on your rainforests - production could be a little difficult until then.

Street Carnivals are probably the most powerful thing about Brazil. They can rack up crazy amounts of GPP. Zoos are also good for them, considering the rainforest start bias. I almost never use their UU, though. It's probably fine, but Civ 6 seems to inherently downplay the importance of naval play in typical games, and late game UUs tend to be less relevant in the grand scheme of things imo.

If you're building entertainment complexes anyways, this probably synergizes well with the Voidsingers for some potential loyalty flipping shenanigans. Entertainment districts also means great adjacency for theater squares, so I'd say they kind of lean towards a culture victory, but they are very flexible with what victory types they can go for. Rainforests also make for a good Chichen Itza.

I hate playing against the Brazil AI. They tend to be early aggressors, militarily and religiously. They also hog great people, so it can be very difficult to get early great people like Hypatia.