Where is area code 393?

There is no area code 393 anywhere in North America (USA, Canada, etc.).

International telephone country code +39 is Italy, and numbers beginning with +39 3 are mobiles (cellphones).

(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, and many other countries use different prefixes.)