Beginners need to know a few things that hopefully are already clear to others, but if you are a beginner, just as in life, the "grown ups" may not follow a culture's etiquette out of ignorance or their belief that the customs of the general population do not apply to them. Argentine tango culture has a lot of wisdom to it, and helps you to have more fun. So please learn some basics. I have danced for many years in Europe, and I can say that tango etiquette not only works but is required in much of Europe and of course in Argentina. Let's start with the an essential element which is NOT in the ballroom or Latin dance community . . . .
The Cabeceo literally means "a nod of the head" which in tango means "let's dance." Another word is "mirada," (the look) which is stupidly is reserved for women, but men may just look and the woman may be the one who nods her head; so think of these as the same. (Watch primates do this perfectly well. It's not rocket science.) It is erroneously believed that only men initiate the cabeceo to get a dance. Smart women have been getting what they want with their eyes, a smile and a nod from the beginning of time. Nothing changed in Argentina or in tango. Attempt to avoid asking for a dance with words; the cabeceo will keep you out of trouble. I don't expect you to believe me, but now I have told you so.