It is public knowledge that when one travels the world, if you do not want to be exposed, you have to be aware of the various customs of the place such as how to greet each other, etc.
Although the most formal greeting when you do not know someone, is to shake hands, they usually introduce you to people in an informal way, and the normal thing is to kiss on the cheek. In some countries they only give one kiss, in Spain for example we give each other two starting from the right cheek, others start from the left, and there are those who give three or four kisses. Even in Russia it is normal for men to greet each other with a kiss on the mouth.
But when we travel to France, things get complicated, because although in most of the country they give two kisses, if you travel north you may be surprised or find yourself in embarrassing situations, since they give four.
In the Deux Sevre region and in Finistere they give only one, and in other areas of France there are three.
The thing is so complicated, that sometimes not even the French themselves know how to greet each other.
To clarify the subject a bit and avoid the odd misunderstanding, you can visit the page combiendebises.free.fr, in which they explain how many kisses are given according to the region that is visited.
As they say: "for tastes there are colors", but I keep our two kisses, since one knows little, three are too many, and four becomes eternal ...