There are no luggage lockers at any train station in Italy, for security reasons. A number of major stations, including Vicenza and Padova, have staffed luggage storage.

https://bagbnb.com/luggage-storage/vicenza/main-station/luggage-storage-train-station?dropOff=2019-11-01T12:00:42%2B01:00&pickUp=2019-11-01T18:00:42%2B01:00&bags=2

thank you, that is good to know about the luggage store option. Still wondering if spending the day in Vicenza or Padova, then taking a late train to Florence sounds like a viable option to anybody.

I do not think you would regret a day in Padua - especially if you get (must do in advance) reservations to visit the Scrovegni Chapel and adjacent museum, a marvelous experience. I'd not be reluctant to arrive in Florence after dark. Might spring for a taxi - if you are luggage laden - to your Florence accommodation.

Do check the hours of operation for any staffed left luggage counter you are planning to use, especially if you are planning a late day train from your day trip city to Florence.

thank you for the info/advice

Ana, Padova or Vicenza depends on your interests. Vicenza has incredible architecture from one of the most important architects in Italy, Palladio. It is also more "intimate" and very Italian. I prefer Vicenza to Padova, the latter being more chaotic and giving more an impression of "big citiy", it has a large university and some areas of towns certainly reflect the high numbers of students, if you get my drift...

Of course, there is the Scrovegni chapel in Padova, worth a visit. Are you into art?

Verona is out of the way, not on the same train line, so I would not stop for the day there.

I would do the day trip, leaving early in the morning, spending a few hours and lunch in Vicenza (or Padova) and continuing to Florence in the evening.