No! Take a train. Europe has a fantastic train system to get to your destination efficiently and safely.
Yes, you absolutely can wait till you arrive to the train station; however, for most bullet trains and some local ones the price often increases the longer you wait to book!
Yes, I recommend "Trenti"! The app will be able to give you the most efficient options to get from Point A to Point B successfully. Trenti will also give you up to date information on your train status like which platform your train is arriving on and if you train is ever late/delayed!
For the majority of Italy that is a no, however download the app "Free Now," that works just like Uber but connects you with a local Taxi driver.
I recommend contacting your phone carrier prior to you leaving so they know you will be out of the country. Often your phone will use international towers to connect you, but most phone carriers will give you the option to upgrade to 5G roaming and high speed internet for a small price.
No, you will need to purchase an outlet converter for Europe, which are very cheap on Amazon!
Since restrictions are always changing, I recommend checking to stay updated on what is necessary to enter any country.