Italy

My sister and I are tentatively planning a trip to Italy in the summer of 2024.  I don't want to go too many places I've been before, and since she doesn't seem to mind skipping out on Rome, it looks like we'll go from Naples to Florence (where I haven't been since 1976) to Milan and Lake Como.

I've read, and heard firsthand, that Naples is "dirty", but given everything that's there, and given that I've never been there, and given its proximity to the Amalfi Coast and Capri, should I really cross that one off the list?

My sister wants to, in her words, eat her way across Tuscany.  I'm ok with that!  I spent the summer of 1976 just north of Livorno; Pisa was a half hour away and Florence was at most a day trip.  I don't really need to go back to Livorno to see the old digs, but basing in Florence and taking day trips to Pisa and Siena seems reasonable.  My sister wants to take at least one cooking class there; that's no problem, as I can occupy myself quite nicely, thankyouverymuch, while she's cooking.

Perhaps I passed through Milan while on the train from Livorno to Germany in '76, but that doesn't count as a visit.  I'd like to use Milan as a base for day trips, especially to the Lake Como area--maybe even get an AirBnB at the lake.

Anyway, that's my plan.  The order of the stops doesn't really matter to me.  Just for smiles and giggles I'm planning on flying to Naples and then taking the train to Florence and Milan, spending maybe 5 days in each place.  If flights out of Florence are cheaper, maybe we could take an overnight sleeper train from Naples to Milan and end the trip in Florence.  That can all be worked out over the next year.

Have you been to any of these areas, or within a day trip of any of them?  I'd love to read your recommendations!