Sicily is big but there are 2 direct daytime intercity trains from Salerno to Siracusa and Palermo (they split at Messina).
Use trenitalia.com to plan in Italy, use March timetables to get an idea. Also French timetables are not complete from April.
Salerno to Sicily
You can take a direct train, where the train gets loaded on the ferry. Search Salerno to Siracusa or Palermo.
Or you can do the crossing of the Messina Strait separately, which is sometimes quicker and certainly offers more options. Search Salerno to Villa S. Giovanni, which is on the mainland.
Then you need to take a catamaran or ferry (frequent departures, buy a ticket on the day for a couple of Euros)
Then search trains from Messina to Siracusa or Palermo.
As @rvdborgt says, schedules for July won’t be published yet. Check dates next week or next month to get an idea.
Sicily to Matera
There’s no train to Matera. I don’t know the area, so you might want to check locally which is the most useful train station, and how to get there. Car/ bus/ taxi?
There’s a train line running from Metaponto to Potenza which passes close (ish) enough for a taxi. But you might prefer to rent a car from a decent-sized town or city.
But you’d definitely start by going back the same way, across the Strait to Vila S Giovanni.
Matera to Paris
Good connections from the south of Italy to Milan or Turin. It’s a long journey, so might be a good candidate for a night train. There are direct TGVs from Milan/ Turin to Paris, hopefully restarting in Spring. There’s a hefty reservation fee to use a railpass. Alternative routes via Switzerland or via local train to Nice - much slower though.
There is a train to Matera but nowadays only via a detour if you're coming from Sicily, since the FAL line from Potenza has been partially replaced by a bus. For timetables see ferrovieappulolucane.it.
If you want to see Matera-style villages, then Sicily is definitely a place where you see more of it.
Of Matera-style, and with railway station, is the city of Ragusa, along a particularly countryside line. Very few trains there so plan well and do take time to get off and really absorb the place!
The more I look into this, Sicily seems a 3 week trip of its own!!!
Me and the future wife are torn now as to what to do.
100% locations are Versailles in France then on to Milan, and Florence, the other locations were sort of fillers as we felt we needed to add some in???
So we could do UK to France 3 days total
France to Milan 3 days total (6 in total)
Milan to Florence 3 days total (9 in total)
Florence to Sicily 10 days total (19 days total)
SIcily to Milan 1 day (20 days total)
Milan to home 1 day (21 days total.
Thoughts? Or can Sicily off and do as a 2 week holiday in the future and maybe add in Rome and Turin? Or somewhere?
Since July is peak season and pretty hot, you might want to relax near the coast and Sicily seems like a good choice. Cities like Rome should be avoided in my opinion.
I've liked Florence a lot, Milan not as much. Perhaps 2 nights would be enough?
There's a convenient night train from Florence to Sicily (one branch to Palermo, the other to Catania/Siracusa). It leaves at around midnight and you wake up during the fun train-ferry crossing into Sicily.
(Like previous summers the classic Florence-Rome mainline could be closed for works meaning a rerouted night train along the coast but I can't find anything yet. It would only mean having dinner in Pisa for example!)
For the way back: you could take a quick flight to the UK but it defeats the purpose I understand! Otherwise I'd use the night train to Milan, cross Switzerland in the daylight, sleep in Strasbourg and then Paris - London at high speed.
Also: the Paris-Milan direct trains don't run at the moment since a landslide in a French valley in August 2023! There is a "direct service" offered but actually it includes a replacement bus across the border adding a good 2h to the journey.
Current predictions mention the line reopening in March-April. Let's wait and see...
The easiest alternative is going via Switzerland: Geneva, Basel, Gotthard,... (Simplon is partially replaced by buses next summer oh well)
