I have a 5 hr layover in Guangzhou Baiyun airport in October.

Since your staying time is so short, it is suggested to shop in the airport, where you can find many kinds of stores.

If you really want to enter the city proper, you can take the airport shuttle bus line 5 to reach Haizhu Square and then change to subway line 6 to Beijing Road which is a paradise for shopping. This method may take a long time.

it is a pity that near the airport, there is no good place for shopping.