Train transfers

It depends, in part, on the train station where the connection is occurring. How big is it? How far apart are the tracks you will be arriving at and departing from? Are stairs involved? How far away is your train car from the entrance/exit from the track? Are you able bodied? Will you be able to easily manage your luggage without assistance? Do you know how to read the arrivals and departures board at the station? Will you have the app downloaded to get real time info on track numbers and any changes?

For most people, 16 to 20 minutes would be ample time, providing their first train arrived on time. What help do you anticipate needing?

That would make me a little nervous too, but if it's the norm it should be ok. As a relative train riding newbie, I google each train station, spot my entry and exit, see how many gates, and sometimes make a print for my travel folder. I found Italian stations to be well marked and I was able to figure out place names easily. Have a wonderful trip!

Where do you need to change trains?

Not familiar with Italian train stations but no worries on fitness and handling suitcase..
First transfer is at Milano to an Intercity train to Monterosso.

Next trip transfer at Milano to Milano airport

If you mean Milano Centrale, you can google it for detailed information. The Man in Seat 61 has photos and descriptions: https://www.seat61.com/stations/milan-centrale.htm

Connections here should be easy since it is a terminus with level connections between tracks.

I thought you were coming from Naples to go to Monterosso. Why are you changing in Milan? That option is at least two hours longer than any other solution.
If you change in Milan coming from Naples then you are likely to travel on a FrecciaRossa high speed train, which tend to be on time (unlike Regional trains). I’m not sure if your change to Monterosso is at Milano Centrale or Milano Rogoredo. I’ve never used Rogoredo, but the station is much smaller than Centrale and with fewer platforms.

The change to the airport coming from Monterosso will likely be at Centrale. If your IC arrives timely then 20 minutes are enough even though the station is large.

If you tell me the exact trains I will tell you the scheduled platforms the trains are supposed to,arrive and depart from.

Robert
Sept 19th
Napoli Centrale to Milano rogeredo 8:55-13.55
Frecciarossa 9310
Transfer window 21 minutes
Milano Rogeredo to Monterosso 14:16-17:05
Intercity 669
i realize this was a bit longer but not knowing the train system I was trying to stay with 1 transfer vs 2 or 3 probably could have cut a few hrs off if i had know system and been more comfortable

Sept 22nd Edit from initial note
Monterosso to Milano Centrale 10:33-13:53
Intercity 666
Transfer window 32 min
Milano Centrale to Malpensa airport 14:25-15.16

Probably should have reached out to folks in advance and go the best advice

Frecciarossa 9310
Napoli Centrale to Milano Rogoredo 8:55-13.55
Scheduled Arrival Binario (Track): no. 7

Intercity 669
Milano Rogoredo to Monterosso 14:16-17:05
Scheduled Arrival Binario (Track): no. 6

The Platform (Marciapiede) of the above tracks (6 and 7) is the same, so you don't have to move at all except for going to the track across the platform from the one you arrive. Obviously that assumes there are no last minute track changes, which (like gate changes at airports) can happen, therefore you must check the displays to ensure the train arrives on the scheduled platform/track.

The next solution is less important, because the train to Malpensa is a Regionale and if you miss it, you can catch the next one, unless you are reckless enough to go to the airport from Monterosso on the same day just before your flight and missing that train would mean missing the flight. So (assuming you are not that reckless), the worst that can happen is that you arrive at the airport 30 min later than planned.

Intercity 666
Monterosso to Milano Centrale 10:33-13:53
Scheduled Arrival Binario (Track): no. 18

Reg. 2952
Milano Centrale to Malpensa airport 14:25-15.16
Scheduled Arrival Binario (Track): no. 1

Milano Centrale is a terminus station (like NYC Central). From Bin. 18 you walk toward Bin. 4. once at no. 4 then you have to walk back along no. 4, because tracks 1 through 3 are a bit set back compared to 4-24. In other words the tracks 1-3 stop before the others. I don't think you will have to walk more than 250 m. so you should be able to walk the distance in about 5 minutes.

Frecciarossa 9310
Napoli Centrale to Milano Rogoredo 8:55-13.55

You have already purchased these tickets? Are they at a fare class that can be changed or refunded? The trip from Naples=>Monterosso is way longer than necessary. Consider:

8:25 Frecciarossa 9622 Napoli to Roma Termini arrives 9:40

9:57 Intercity 510 Roma Termini to Monterosso 14:25 [vs 17:05]

If you can't change the tickets, you could get off the 9310 early at Firenze and then buy a ticket through to Monterosso via Pisa - you would save more than two hours - arriving 14:53. I know it's one more stop, but to me the additional cost of another ticket would be worth it.

Markcw which firenze station ......the train ticket site shows 3 or 4 different ones
I can't cancel the 9310 so my option based on your idea is get off firenze (?) and purchase a new ticket to monterosso
Tuscany line 4029/innercity 674?
This would be firenze SM Novella correct?

Your train from Naples stops at only one station in Florence, Firenze S.M.N. That is the main train station in Florence.

Yes, those trains are the ones you want.

Sam has it right.

Don't sweat the changes - easy once you've done it. You should be able to find YouTube videos for navigating the Firenze S,M. station, and others cover the general topic of riding Italian trains.

If you're looking at the train display boards in the stations to find your track, look first for the train number, as the destination displayed may not be your stop. There's also a way to view the station departure and arrival boards within the Trenitalia app - I forget exactly where it is - but it would enable you to find the track number for the upcoming train before you arrive at the station.

Edited to add: be mindful of how to validate your new tickets - either within the app, or paper tickets if not purchased until Firenze.