A difficult “Hello”

I have been in four countries through my life; Canada, Brazil, Argentina and the US. The most difficult part related to the culture was and still is (I am still in the US) how to say Hello. In my country we (women, and some men) say hello with a kiss, even if we do not know the person; it is rude when you shake their hand. For boys that is ok, but for girls it is not. For example in Argentina and Brazil the way to say hi is the same as in Chile, but in Canada and the US it is colder. Sometimes I do not know how to say hello here; it is always an awkward moment, because some guys move their heads, others shake your hand and others give you a hug, and some do not say anything, but they never kiss. Moreover, now that I am in CESL, I have met different friends from different countries also. Saudi Arabians shake hands and kiss at the same time, but Asians give hugs, or just say hello. I could say that the language and maybe food are the most difficult cultural problem that people could have, but something so basic as a “Hello” could produce serious headaches.