A question, I am Argentine and am in China, I would visit Macau for a day or two, I need a visa?

Dario, you needn't apply one in advance. After you arrive there, you can apply for the entry permit. It costs around MOP100. And you at least should have MOP 5000 and return air ticket in hands. These two things ensure that you can support yourself during your stay. And you will leave soon.