Transportation help!

Did you consider flying IN to Milan, OUT of Rome?
Multi- city or open jaw ticket

I doubt flying would save time once you add transit to / from airports, security, baggage etc
The whole trip can be done by train.

Hello, yes we booked the round trip flights already. It was significantly cheaper to book round trip flights in and out of Rome.

I am doing something similar next month, with separate a separate second ticket on from FCO to Catania. From what I have reviewed you need to be sure you understand the second carrier's check in policies, baggage allowance (both checked and in the cabin), and which terminal at FCO you might expect for arrival and departure to plan your route and time needed and understand that of course your connection is not protected and you may have to come up with a plan B on the spot at your own expense.

The train !!!! ---- all those locations are well served via frequent trains. Rail travel is cheap in Italy. A car would be problem especially when it comes to parking. And Italy is known for its restricted driving zones and give you a nice reminder of your trip about nine months later. You don't need a car.

You are way better off with the train to Milan rather than a flight, especially since you are overnighting in Rome when you arrive. And the whole trip is best done by train.

The train goes city center to city center Rome to Milan in 3 hours 10 minutes. If you were to fly, you would have to return to the airport (1 hour?) 2 hours before your flight, take the flight, then get transport from the Milan airport into the central train station (another hour) for the train to Varenna on Lake Como (if that is where you plan to stay). That is about 2 hours extra to fly.

As for the rental car, it does not make sense with your itinerary, especially for first-timers in Italy. Driving long distances there is not fun, and parking at your arrival places (or in Pisa) may not be easy. Most cities have ZTL’s where private cars are not allowed without a resident’s permit; they are not always clearly marked. It is very easy to slip inside one without noticing, and you will get a pricy ticket in the mail 6 months later. We (my husband and I) are about the only people we know who have NOT gotten such a ticket, or a speeding ticket, after renting a car in italy. And so we do not press our luck, we are not going to drive in Italy ever again.

The places you want to visit are easily reached by train, apart from the Tuscany wineries which you plan to do with a private driver anyway (good idea). The trains are easy to use, with a bit of coaching from people here for your first ride. After that you will be experts.

I assume we are talking this coming June? And you do have your lodging at Lake Como for the wedding portion? (Where is that, by the way). You may have difficulty finding lodging in the Cinque Terre at this late datfe, so be prepared to consider alternatives.

Whoa, sometimes a round trip ticket initially sounds cheaper but with all you want to do, may end up costing you more in time and money. I hope someone can help you with this.

Back to the OP. I would not fly to Milan from Rome. A train takes roughly 3 hours, or a bit more. Your one hour flight takes 2 extra hours at the airport before your flight+ time just getting to the airport. So you are taking longer and complicating the whole process.

Where on Lake Como are you staying? Como? Varenna? Bellagio? Depending on the wedding particulars, you may be able to get around by train/ferry/taxi (and if letting your hair down at the wedding parties, be very mindful of the lower allowable blood alcohol limits if driving.)

None of your other transfers require a car, and are an absolute headache in some. All are accessible by frequent trains. Are you actually staying in la Spezia instead of staying in one of the CT villages? Seems like an unusual choice.

Thank you! Yes, every hotel/air bnb was booked a few months ago in the cities I listed. We are staying in La Spezia, not in the cute Cinque Terre villages, but I'd love to explore them during the day/hike. I read the train system there was pretty extensive. Worried about the crowds though as well. I held off on booking transportation during the initial planning a few months ago/when I booked our hotels. Now being two months out, I really want to finalize transportation and iron out the itinerary/details still ahead of time :)

We are staying at the Hotel Bazzoni in Lake Como. Are trains safe as far as theft goes? Stolen luggage?

Trains are perfectly safe
Why would anyone want your underwear?
Your valuables should be on your person or in your hands

Exactly which town on Lake Como?

ETA
Ok that hotel is in Tremezzo which is across the lake from Bellagio
I’ll let others help you with that transit

Has the wedding couple shared any transportation info with guests?

I'm so paranoid my luggage will get lost lol and Via Regina, 26, 22019 Tremezzo CO, Italy is our Hotel's address in Lake Como.

Yes once we get to our Hotel, transportation has been arranged for the wedding etc. The couple's wedding we are going to usually take private transportation from Milan to their Hotel in Lake Como. I was probably going to go that route if we take the train from Rome to Milan. Then pay for private car to Lake Como. ???

You will be handling your luggage on/off trains, you will not be leaving it anywhere
It will always be in your sight

More chance of airlines losing it!

Looks like you will train from Milano Centrale to Como (the town) then take a bus to Tremezzo

You have plenty of time to book your trains so don’t panic

The schedule past June 9 is not even up yet and several of your trains will be regional-those cannot sell out and price never changes

We have ridden trains all over Europe for nearly 40 years. Haven't lost a bag yet. Of course there is always next trip. I know, I know, pickpockets and casual theft is frequently discussed here but petty theft is really minor. You are not traveling i in a den of thieves.

Hi Ellen - to clarify:

We will be flying in and out of Rome roundtrip June 19th-July4th.
Staying first night in Rome 21st and next morning heading to Lake Como
(for a wedding) June 21-25th,

I think you meant that you're flying into Rome on the 20th and moving on to L. Como on the 21st? :O)
You'll be on Lake Como (exactly where on the lake? ) the nights of the 21st, 22nd, 23rd and 24th.

Moving on to La Spezia for nights of the the 25th, 26th and 27th. Honestly, La Spezia isn't what I'd choose for the CT. If you can't get an accommodation in any of the 5 villages, look at Levanto as it's nicer than LP. You'd be wasting money to have a rental car sitting unused for several days: take a train from Lake Como and trains/ferries around the coast. Spend some time with the CT website for info on the trail system: not every segment will be open.

https://www.parconazionale5terre.it/Eindex.php
https://www.parconazionale5terre.it/Esentieri-outdoor.php (a black line on the map means that trail segment is closed, and additional segments could close to damage or weather at any time.).

Moving on to Florence for the nights of the 28th, 29th and 30th with a stop in Pisa. This only gives you 2 full days + some odd hours for Florence: not a lot of time to take in an important Italian city let alone leave that city to visit wineries. No need for a car, and I personally wouldn't leave luggage in an unattended vehicle while sightseeing anyway. If you must see Pisa, store your luggage at/near the train station.

On to Rome by train for the nights of the 1st, 2nd, 3rd. Flying home on the 4th. You'd have 2 and 1/2 days for this city....which is pretty short.

If you were dedicating quality time to stays in/exploring rural Tuscany, I'd be OK with the car but I don't see the benefit for your itinerary as it stands.
Editing to add: While I was typing you added the info about your hotel in Tremezzo.

The couple's wedding we are going to usually take private
transportation from Milan to their Hotel in Lake Como. I was probably
going to go that route if we take the train from Rome to Milan. Then
pay for private car to Lake Como. ???

This is probably your best choice. It won't be the cheapest but it will be the easiest. I would ask them for a recommendation for driver.

So you'll take a fast train from Rome to Milano Centrale. Then meet your driver to take you to Tremezzo. Reverse that after the wedding and catch a train to La Spezia from Milano Centrale.-For this route there are IC trains with no changes or regional trains with at least 1 change.

From La Spezia to Florence is also easy. A lot of the trains have a change in Pisa so you could make that stop- store your luggage at train station.

From Florence to Roma Termini- fast train direct, several each day-hourly or more

Here is the official Trenitalia site:
https://www.trenitalia.com/content/tcom/en.html

You may not see all trains for your dates until closer to June 9 update but you can look at same day of week now to get idea of offerings- they don't change much.

Station names are:

Roma Termini
Milano Centrale
La Spezia Centrale
Pisa Centrale
Firenze SM Novella

Everything you need to know about train travel in Italy here:
https://www.seat61.com/train-travel-in-italy.htm
(except purchase your tickets on the official site- not ItaliaRail ( a third party reseller)

From the airport- you can take The Leonardo Express into Roma Termini- pretty easy and cheap 15 euros/person?
Or just go out front, get in taxi line and take a taxi right to your hotel- fixed rate 50 euros.