My understanding is that there is no 1st, 2nd class distinction on regional trains. We rode one a couple of years ago Naples to Pompeii, and it was just "grab a seat", however, for our upcoming trip this summer on Trenord from Milan to Varenna and back, the schedule provides a 1st Class option. Just curious what the benefits may be, as I do not find a link on Trenord's website to distinguish. Anyone with first hand knowledge?

Peruse the following info-laden sites for a look at classes: www.budgeteuropetravel.com; www.ricksteves.com and www.seat61.com.

First class is always more relaxed - usually empty seats - no seat reservations on that train which takes 1 h 2min to go MIlan Cenrale to Varenna and leave every hour. Italian trains do at times have first class - the train you took to Naples-Pompeii was a commuter train, just like a metro so no classes. Best to buy your tickets to Varenna at Milan Airport train station - no advantage I believe in buying ahead - flat fare and again n seat reservations.

Thank you. We have train tickets "in hand" for all other trips using iTalo, and only lack a RT Milan to Varenna. I'll book 1st class on Trenord on the 8th or 9th.

Again booking is not needed on that train and can buy return ticket in Milan - flat fare - no seat reservations - if you by online be very sure of the 4-hour windows of use those tickets have (or however long for validity they are) - ones bought at station can be used all day on any train. so yes booking does not mean booking anything but having a ticket for a regional train - same as you'd buy at stations but for convenience yes but do look a lengths of validity when booking. Varenna-Esino is the official name of Varenna station.

And I believe you have to cancel regional train tickets before boarding -paper tickets by sticking in validating machines that date stamp them - probably can do on phone too but I know nothing about that.

You can spend more for 1st class. I wouldn't, but that's me. The ride is just an hour long, and I like to be ready and waiting with luggage at the doors when the train stops at Varenna for just 4 minutes.

I don't understand PalenQ's recommendation that it's "best to buy your tickets to Varenna at Milan Airport train station" unless you're actually starting this journey at Malpensa. You can certainly buy Milan-Varenna tickets at the airport, but you can also buy them at the Milano Centrale train station or any other Trenitalia station if you're coming from elsewhere in Italy or on the Trenitalia website. The price will be the same

https://www.trenitalia.com/en.html
[Search Milano Centrale and Varenna-Esino.]

It is advisable (but not absolutely necessary) to buy your return tickets (to Milan or another destination) at the same time you buy the outbound tickets.

Don't underestimate the queues at Milano Centrale ticket counters and often even at the ticket machines.
After arrival at Varenna, ask in which bar or grocery you will have to buy your ticket for the way back.

I thought they were coming from airport and going same day to Varenna but no so yes buy those tickets at MIlano Centrale or in advance - same price - no seat reservations possible.

Or buy them at another station if coming from elsewhere in Italy. Or buy them online.

There is also a ticket machine at the Varenna-Esino station, but I would have already purchased the return/onward ticket before arrival in Varenna. That's just me. I don't like having to track down stuff like this after I arrive.

Thank you all for your comments. It will be our 5th day in Italy, and we will be taking the iTalo fast train from Verona to Milan Centrale and then a regional up to Varenna-Esino. After a couple of days in Varenna, we head to Florence, and again I have my iTalo fast train tickets from Milan Centrale to Florence SMN, and just need the regional. As a "belt and suspenders" type of person, I like to get the travel and accomodations completed before leaving home (sample picture attached). I have the iTalo app on my phone for the bar code ticket, but I have also printed out all the tickets too. If an additional 10€ a ticket will get us storage above our seat for carry-on luggage, and a bit wider seat, then it will be worth it to me.

Don't get so comfortable that you aren't ready to get off at the Varenna stop.

.... we'll try not to...

All classes on regional trains have luggage storage above the seat, for small suitcases. The storage in 1st class is the same, but there are fewer people using it. There are different models of regional train, but I've never seen one where the over-the-seat luggage rack would accomodate a larger suitcase.