14 night itinerary help so far only airfare is booked

Just returned from 14 day trip- half in France and half in Cinque Terre and Florence. Our second trip to both places. Do not recommend renting a car in the Cinque Terre or to come to the C.T.- very little parking. Take trains or hike between towns. You can take easily take train from Florence or Milan to C.T. but I would recommend more than 1 night in the C.T., especially if you want to hike. There are the easier blue trails and the more difficult red and white trails. We hiked from Corniglia to Vernazza on the Red trail. Challenging by very worth it! We spent 3 nights and found it to be the most relaxing part of our trip. I would recommend that your lodging has views of Med.
Years ago, we took train from C.T. to Pisa. Rented car and had home base out of Volterra ( excellent Etruscan Museum and at least at that time, less touristy), then day trips to other hill towns. Sienna, Sam Gimignano, Montepulciano and Florence. This time, we spent 3 days in Florence. Good luck!

Your trip would flow better if you did this.

Arrive MXP. Fly to Rome
You're already at the airport, use a flight (easy jet 1H52m) to get to the farthest location.

Train: Rome- CT 3H48m

Edit: train Rome-Florence 90m.
Skip CT and add those days elsewhere. Pick up rental car Florence. Or use busses to explore Tuscany from Florence.
You won't see as much, but you will not get tickets passing thru the dreaded ZTLs.

CT-Tuscany. Rent car after your stay in La Spezia.

Tuscany-Venice. Dependent on where you stay, you have to decide if it's easier to drop the car in Florence (FLR) and bus to the train or drive to Venice and drop the car there. Train is 2H05m.

Train: Venice-Varenna 4H24m

Train: Varenna-MXP 2H05 m.
Early flight? Head to the airport the night before.

You should try to spend no less than 2 nights in the same place.
My recommended number of minimum nights:
Varenna 2
Venice 2 or 3
Florence 2 or 3 (or more if you use Florence as a base to visit Tuscany)
Cinque Terre 2
Rome: 3 or 4
Tuscany (by car): 3+
Tuscany (without car) add the above nights to Florence and use Florence as your base for day trips.

Be aware that the end of October is statistically the rainiest time of the year. If it rains, neither lake Como, nor the Cinque Terre will be particularly enjoyable.

A car is nice to have while visiting the Tuscan countryside and small villages. You could rent it in La Spezia, near the Cinque Terre, on your way out of there. Or you could visit Tuscany after Rome on your way back north to Milan. In that case your itinerary would be:
Milan Varenna Venice Florence Cinque Terre Rome Tuscany Milan.
In the above case you could rent a car in Rome to visit Tuscany on the way north.
If you decide not to rent a car and do by train then the itinerary could be the same except that Florence and Tuscany are visited from Florence, then from Rome you go straight to Milan to catch your plane. The last night must be spent in Milan or close to the Milan Malpensa airport. Rome or Florence are too far from the Milan airports.

That's how I felt! We go end of September. I finally decided to just fly to Milan leave immediately for Rome. 4 nights there, 1 arrival,1 jet lag and evening tour, 1 day underground Colliseum, and 1 day Vatican. Then to Florence 4 nights, day trips to Tuscany and maybe Siena. I haven't booked any other Trips but Rome, after Florence 3 nights Venice then to Milan one night. It seemed like going to a lot more places was a lot of travel time on the train and rushed. I get back Oct 4th and can fill you in then.

So you leave NYC on Friday 21 October and arrive Milan Saturday 22 October, right? What day, date and time is your flight back to NYC from Milan?

Just trying to zero in on how many nights you actually have in Italy and the potential that you'll need to spend your last night near MXP.

Update: I forgot to add what I think is a possibly good option for doing some of the things you want to do without renting a car and driving in Italy, which might be more of a challenge than you want to take on for this first trip. Walkabout Florence has many tours still running during the time you will be there. I've been on the Best of Tuscany one with my husband, daughter and granddaughter. We all had a blast.

There are others on the linked page that sound great. They may seem expensive, but they could be much cheaper than renting a car, driving it too fast or somewhere you shouldn't and ending up with hefty fines when you get home. See the many forum postings related to that, especially for Italy.

You are trying to go to too many places in 14 days. Those are not destinations you can see in a few hours (well, maybe Varenna if you don't want to see anything else on Lake Como).

Consider that every change of hotel requires you to pack, get to the new city, check into the new hotel, and get settled. If you aren't driving (and on at least some of your legs the train will be faster, and without parking issues), you must get yourself to and from train stations. So look at train times on the Deutsche Bahn website and add at least two hours for each transfer, probably longer. When are you going to have time to see Italy?

Given the warnings about possibly rainy weather in late October, I'd drop some of the northern destinations and keep Rome. If you were traveling in the summer, I'd suggest dropping Rome.

Venice, Florence and Rome all have enjoyable indoor sights. Varenna and the Cinque Terre, not so much. Although it's not generally recommended for logistical reasons, you could have a short day-trip to the Cinque Terre from Florence, making arrangements once you arrive if the weather is predicted to be good. Or there might still be one-day bus tours running in late October. Of course, the latter option will cost more.

It is amazing the amount of time "lost" getting from one place to another. It almost always take longer than one plans. Listen to Roberto. "You should try to spend no less than 2 nights in the same place." My recommendation is 3 nights in one place when possible. That really only gives you 2 full days and part of the arrival day. Just food for thought.

wow, thank you all for the insightful comments. I think it makes sense to do what a few of you suggest and fly right to Rome after we land in Milan. And Lo, yes you are right, i got my days mixed up. We leave NYC on friday October 21st and land in Milan at 10:40 am saturday the 22nd. There is a 12:15 flight to Rome on Alitalia that i am thinking we should be able to make. Yes?
It does seem like i am squeezing in a little too much with all the packing up, i do want to relax and enjoy Italy too.
We could spend 3 nights in Rome; get a rental car and drive to tuscany for 3 nights, return the car in La Spezia. Spend 2 nights in Cinque Terre, (weather permitting), take the train to Florence for 2 nights. Then train to Venice for 3 nights. After Venice head back to Milan and stay the night before our flight leaves there. I may have to skip the Lake towns. The only way it will work is if CT is rained out and i can move everything else up.
The walkabout tours sound great but i wanted to do more than just a day trip to tuscany.
JDV81- can't wait to hear how your trip turned out!

does this sound better?

OK somebody got in your in you head that you should fly to Rome immediately after you arrive in Milan, but you already have bought round trip from JFK to MXP. Can you tag on another flight afterward? Maybe, but you should make serious inquiries that you can do that and get your luggage automatically transferred. In other words you are changing your ticket from a simple round trip to an openjaw trip to Rome with a change of planes in MXP, then flying back to JFK from MXP. Get this settled at once before you go any further, or forget that idea and proceed with the ticket you have.

So recapping some of the good advice you already got.
2 nights Varenna: Relax, jetlag recovery
3 nights Venice: so you get 2 full days
5 nights Florence: Look at an apartment and rent a car for 1 day to explore Tuscany
3 nights Rome
1 night Milan: before flight home

Now you can book train tickets with advance discount fares, except 1st day because these a regional tickets and the cheap price doesn't change. Tweak Florence and Rome days according to things you want to do.

To elaborate on what Sam said . . . unless you can add to your existing flight, you will be $hit out of luck if you don't make the connection. You have no idea if you will land on time or how long it will take to go through passport control. If you are on a connecting flight the airline that sold you the ticket has the responsibility to get you to your destination. If you are delayed getting to it in Milan, they'll figure out a way to get you and your luggage there. If you buy a separate ticket, it's strictly your problem. If you miss the flight to Rome, chances are you can just toss that ticket in the nearest recycle bin and buy a full price ticket on the spot for the next available plane.