Zonda refers to the Pagani Zonda, an Italian high-performance sports car. It's a very specific and luxurious car model, making it an interesting and unique word choice for a song.
Lazza repeatedly mentions the Zonda throughout the song, using it as a symbol of speed, wealth, and success. For example, he raps, "Corro su una Zonda, Zonda Pagani, Ludovica" (I'm racing on a Zonda, Zonda Pagani, Ludovica), emphasizing his fast-paced lifestyle and achievements.
ZONDA is Lazza driving flat out, and using the car as a way to talk about his own career. The Pagani Zonda is the reward he bet everything on ("all in su una Zonda"), and it is also how the whole track feels: two hundred an hour with the headlights off, brushing the guard-rail, betting that nothing goes wrong.
Underneath the speed there is a lot of settling of scores. People have talked about him, so he answers by digging their grave and telling his mother he is on air. He measures himself against rappers he sees as decorated rather than real: fingers full of rings, fillers in their faces, gold diggers who want to redo their looks, and contracts with four zeros that he refuses to be grateful for.
The last verse is the most honest part. He says he will end up in a morgue if people stop shouting his name, that a rival's show draws half an oratory while his drew half a football terrace, and that he was already one of the real ones before the blue tick arrived. The bravado and the fear of being forgotten sit in the same lines.
For learners, this song is a good place to hear fast, modern Milanese rap: short punchy sentences, doubled words at the end of a line for emphasis ("tomba, tomba", "onda, onda"), and everyday slang like "fra'" for brother.