Here it is an article which has to become your travel Bible to be used before coming to Italy, in order to be ready. Read it, learn it, then come to visit me and we will have a total blast, believe me!
1. If you can speak Italian, just do it. Even if you can only say “ciao” e “grazie”. As you know not all the people in my country speak Italian, especially if you go in small town like the one where I grew up! If you speak English to someone in the street, you don’t get an answer back. People find tourists annoying, since they come to Italy without even talk Italian.
2. “Arrivederci” is not used as much as the English “bye”. It is more formal, something like “goodbye”. We prefer using “a presto”, which means “see you soon” (if you talk to friends) or “I’ll come back soon” (if you purchase something in a shop).