margeandconnie -
Yes, a little more info would be helpful
So they are arriving in Rome from JFK on June 20th (as Nigel asked, on a COVID Secure flight?)
Leaving from Milan Malpensa to JFK
.... and hope to visit Venice and leave from Milan
Does this mean they haven't purchased their air yet - although I've a feeling that they have - or just that they'd like to see Venice?
Do the 6 days include arrival and departure days, meaning they'd arrive in June 20 and fly home on June 25th? Or are they flying home on the 26th? Either way, it's a very short time for 3 locations: 4.5 days or 5.5 days on the ground in Italy.
Not sure what their nightly budget is; I would expect even a private hostel room for 2 during high season to run over $100 U.S. per night but I haven't checked. If they're a couple, pretty sure they're not interested in a shared dorm (I wouldn't advise it).
If 5.5 days:
June 20th: land at Fiumicino, transport into central Rome, find their hostel (The Beehive is close to Termini and has gotten rave reviews for years) and walk around some to get acclimated. Shuttle buses into Termini (Rome's most central train station) from the airport are very inexpensive, although they take a bit longer than the express train.
https://www.adr.it/en/web/aeroporti-di-roma-en-/pax-fco-bus
https://www.the-beehive.com
June 21st: Rome sightseeing
June 22nd: Rome sightseeing
June 23rd - Train to Venice, find their pre-booked accommodation (sorry, I don't have a hostel reco for this one) and get acclimated.
June 24th - Venice sightseeing
June 25th - train to Milan; some sightseeing and overnight (sorry, no reco for a hostel here)
June 26th - AM train or shuttle bus to Malpensa; fly home
Yes, what they want to see and do is important to know as some attractions require advance reservations - or they'll want them to avoid standing in a potentially long, hot queue - that they'd want to jump on ASAP.