Meet & Greet
In Spanish speaking countries, people that don't know each other well, typically greet each other with a handshake if they are in a formal setting. In more informal settings, male friends or family members usually greet each other with a hug (abrazo) or a pat on the back. Women greet each other and their male friends with one (Latin America) or two (Spain) kisses (beso) on the cheek.
You typically address a person you don't know well by Señor/Señora and their first (paternal) last name. For example, María García Sánchez is addressed as Señora García.
For formal situations you use usted to address someone, in informal situations (with friends and family) you use tú.