Rome cruise port to Rome and storing luggage near train station

It depends on your time line. The best way is a private driver pick up. Probably 150 to 200 euro. Luggage storage with a private driver could be a problem. You can take the train from the cruise port -- about an hour depending on train -- to Termini. From ship to Rome could take a couple of hours. This is a big luggage storage on the lower level of Termini. From Termini take a taxi to the Vatican and return. And then the train to Naples. What time is mass?

hey hey travelingNana
when is this trip and how many is "we"? so much to think about this adventure.
what's the earliest you can get off ship, what time is mass? read very carefully the rules of luggage storage (costs, hours open & closed, size of lockers for bag size how many bags, how easy to get in, check in bags, get to mass, getting back to train station for ride to naples). i would reserve a cab at cruise port, with so many cruisers getting off and finding transportation like you with all the crowds, pushy/nasty people all in a hurry.
cab to mass and cab back to roma termini to get bags and hop on train. sounds stressful but to me best way. if you decide to do public transportation, do you have it all marked, how long, probably hours, until you get back to train station. this is not the time to be cost conscious if mass is important to you. good luck
aloha

Where in Rome are you thinking of attending Mass?

Civitavecchia (the port town) has a really nice Cathedral (missed by 99.9% of cruise passengers, and yes I've been to the Cathedral when in Civi on a cruise)- https://cattedralecivitavecchia.it/orario_ss-messe/

You could go to Mass first there, then afterwards take one of the fast long distance Inter City trains from Civitavecchia to Rome, changing for Naples. They are totally different to the commuter trains which the vast majority of cruise passengers take.

Say you got to a Ferial (non festal day) 0930 Mass at Civi Cathedral there is an 1116 Frec train from Civitavechia. Yes it's more expensive than the commuter train but is a maximum price of 16 Euro from Civi to Rome.

In Civitavecchia would we find luggage storage while we attend Mass?

https://radicalstorage.com/luggage-storage/civitavecchia/railway-station/luggage-storage-civitavecchia-railway-station
This one is at the railway station in Civitavechhia. Several others also show up on a Google search.

hey hey
love the idea of isn31c to attend mass at the cruise port civitavecchia church.
no need traveling into rome for a mass. plus "carol now retired" posted about lockers at the train station. look into it, how much cost is for bags and how many bags, hours of operation. is there a shuttle from port to train station, how far is it to walk to church, attend mass and return to train station, pick up bags, buy tickets to naples.
check to see if church offers you to place bags in church while attending mass. that's another option, "killing two birds with one stone" it will be a long ride, if small shops at station, buy some food to have along for the ride. on some long ride we have bought bread, salami, cheese, drink, bottle of wine (always carry a corkscrew) and enjoyed the ride. make sure you validate ticket before boarding.
look to see if a market place that sells goodies.

do more research, have all your ducks in a row to store bags after cruise, enjoy mass, easy ride to naples without stress. good luck
OP has not returned, maybe she has got an answer elsewhere.
aloha

or you could attend Mass at the big church in Vatican City - that would be a great memory