Wear very very comforable tennis shoes (sneakers). Pack light - probably should read and try to follow Rick Steve’s packing guides to some extent - Italy is a modern country and anything you forgot can be purchased.
Vatican City - know the dress code BEFORE you go! Basically avoid shorts and sleeveless blouses and no tank tops etc. Rick Steves has that too and it is online too.
For hopes of conversion of son ec - be sure to visit St. Peter’s grotto - the downstairs of the basilica as well as the upstairs (the main church) Downstairs has the tomb of St. Peter, tombs of many popes. Research St. Peters - several other Apostles are buried there along with St. Peter. I know these make a big impression on lots of lapsed Catholics and also on Protestants - to stand next to the tomb where St. Peter was buried brings the realities of the Gospels alive in a certain way.
Be sure to visit the Pantheon! It was the lagest dome in the world up until 1960 I read once. As you will see, most of the Roman ruins are just that - ruins (still fascinating) stripped of there marble sometimes down to the ancient Roman brick beneath (yes Roman’s used bricks too!) The Pantheon is one of the if not the best preserved ancient building of the Roman Empire - the multi-colored and inlaid marble inside is exquisite. This building shows you what the other Roman temples etc looked like before they were sacked for their marble etc. It is magnificent.
Italians eat dinner later - reservations are usually essential for dinner - your guide book (be sure to buy one - i like rick steves because his maps of the sites make sure to point you to the highlights of each site) will have places to eat and numbers for reservations which can be made that day usually but again guide book will have this.
if in restuarant - knwo the meal structure - italians have first course [primero] (usually pasta) and a second course [segundo i think] - usually a meat type dish - portions are smaller.
A meal in a restaurant is a joy - not like here where they rush - they eat leisurely and have wine and just enjoy it all - we had things to do so had to get up and get our check!
or can just always eat stuff on the go.
after their late leisurely dinner, Italians take a stroll in the night air after the sun goes down (since it is hot in their apartments etc) and just enjoy the evening - leisurely strolling and eating gelatto etc.
BE sure to visit Piazza Navona at night - this large square was once th eseen of chariot races and the shape of the builings around it shows it. At night clusters of people gather - some sing and play musical instruments spontaneouosly - eat dessert here too – there used to be a finger dancer guy - he sets up a littlel table and with his painted fingers puts on a finger like puppet show using little flashlights as spotlights on the fingers. it is amazing!!!
vaticna museums are awesome and must be seen - read guide books for advice on when to see it etc.
start out each day early, even though the walking will make you tired. pace yourself - take food breaks where you sit down, to give your feet a rest.
restaurants will ask if you want gas or no gas in your bottled water (they do not give free water like here in US - the water has carbonization (gas) or does not (no gas) sometimes bread cost money too, and
important - usually tip is ADDED into the price so do not tip again!!
bring converter plug kit (Target etc has them in travel section) if appliances do not already auto-convert to worlwide voltages) and plugs are differrent too.
Money belt (neck kind i like) essential - pickpockets abound.
Luggage lock good to - tsa approved available at target travel section - if you check in early or leave luggage with hotel for a few hours after checking out while seeing some more sites, you’ll feel better knowing it is locked.