May I leave the airport (Guangzhou) if I only have 5 hours layover?

Hi sir/madam,

I am collecting some important documents from my relatives in Guangzhou airport. Thus I may need to pass the immigration to the arrival hall. Do I need a visa to leave the gate area to go to the arrival hall please? Do you mind to give me more information.

I am travelling from NYC to Sydney, with 1 transit in Guangzhou for 5 hours. I am holding a Portuguese passport but I am originally from Macau. It is an accidence that I have left my Mainland travel permit or HK and Macau residents in Macau so my relative is going to bring it back to me.

And then should I go back in the gate area with my permit or passport.

Cheers,
Cecilia