I always thought Italians were friendly

[Bread and Circuses]

4. Were you speaking Italian? There's a way that Europeans address or greet each other....that may be different .

For example. In Italy, there may be less interest in greeting tourists or unknown people as the country has many ex-pats, EU residents, etc. They have lots of non-natives in Italy and they will be cordial but not interested in getting to know you or chatting. Don’t take that to mean that they are less friendly. . If they see you more often in the streets, stores or piazzas they will be more likely to chat and smile. They are not prone to wave to strangers, it just isn’t a common thing. They like to build a relationship over time .
Waving to strangers across the piazza is not what most other cultures do. Of course, this is a generalization.
When traveling, I’ve found that it’s best to be in the background, blend-in and observe. Also, to know some phrases in the local language. And, people have helped me of I look bewildered or lost.

Enjoy your travels.