do I need a Visa Transit (G-Visa) ?

Hi, I'm French (so European Passport), and I'll have a transit of 2 hours 50 at Guangzhou Baiyun Airport on my way to Singapore (I don't intend to go out from the airport) and then, on my way back, I'll have a transit of 14 hours 40 at Guangzhou Baiyun Airport (I may want to go out of the airport during that waiting time but nothing sure), I saw somewhere that 'Anyone desiring to go beyond the airport boundaries temporarily should obtain permission from the frontier inspection office', does that mean that I could get the permission once arriving at Guangzhou Baiyun Airport?