Greetings have in fact been studied extensively by anthropologists and even by ethologists. For example, Irenäus Eibl-Eibesfeldt describes many of them in some of his books. Not much practical advice but truly surprising stuff. For example, spitting on the palm of your hand and rubbing it on the other person's face, or turning around and bending forward to present your naked buttocks and genitals are two ways to greet strangers that are (or were?) reportedly practiced in some human societies.
In Europe, I have mostly seen handshakes, kisses on the cheek, hand-waving or other gestures without physical contact, and hugs (possibly together with kisses and a handshake) but the details also vary a lot between countries and social settings: you kiss twice, three or four times; you only kiss people you already know or only between women or between a man and woman more rarely between men, handshakes might be for the first time you meet, once a year, or every day. Fist bumps seem extremely rare, to me it's something teenagers could do while being fully aware that it's not the regular way to greet. Bringing your hand back on your chest after shaking hands is rare but I have seen it too.
Because of this, mistakes happen all the time to European people as well, just be alert and don't worry too much about doing it wrong. At the end of the day, I think foreigners have some leeway in this and I don't think anybody is likely to be offended. Usually a misstep would just start a short conversation. Don't be afraid to comment on it if you feel some awkwardness, people will likely be happy to explain and have some way to overcome the awkwardness.