1st time to Italy

Aziana, welcome to the forum. So that you are aware, we are just a volunteer group of travelers like yourself. Occasionally, someone out of the goodness of their heart might pencil out an itinerary, but it tends to work best if you review a travel guide, pencil in something that you think might work, and we help move it to something a little more solid in shape.
Keep in mind that every city move tends to eat up half a day.
Rome2rio is a good website for plotting out sequence of travel stops - it recommends various modes of transport so it helps with judging travel times....also any needless backtracking or overlapping.
seat61 dot com is a great website for train travel advice....and train is most likely the most practical way to get around Italy.
As September is still considered high season in Italy, you will want to move on your accommodations bookings soon.

First time to Italy and no Venice? I would try to squeeze Venice in, if you can.

My plan (without a car, only trains and buses)

Fly to Venice (VCE)
Venice: 3 nights
Train to Florence
Florence: 5 nights (use Florence as base for extra days for day trips within Tuscany)
Train all the way to Sorrento.
Sorrento: 4 or 5 nights (use as base for Naples, Amalfi Coast, Capri Island, Pompeii)
Train to Rome.
Rome: 4 nights
Fly home from Rome (FCO)

The above is 17 nights on the ground.

I did not include the Cinque Terre since you are going to Amalfi Coast which I think it’s better. However if you want you can add a couple of nights at Cinque Terre (after Florence or before). You could also add an extra night in Florence and visit Cinque Terre as a day trip from Florence. A long day (2.5 hours by train each way) but doable.

Perugia is not in Tuscany, it’s in Umbria. It’s 2 hours from Florence by train. You could meet your friends for a day, or if you prefer you can add a couple of nights to your overall trip and spend those nights in Perugia right after Florence (before Sorrento). I would probably choose to stay 3 nights in Perugia or nearby Assisi. Of course visiting Assisi is a must since you are in the area.

Thank you Maria and Roberto for your suggestions and recommendations. I will outline a travel schedule and will post the draft and look forward to some feedback. Aziana

I second Roberto, Venice must be included. Visited Italy for the first time last November for 10 days and managed to visit Florence, Venice, Rome & Pisa (had to see the leaning tower). It was tight but I will do it all over again any day. We used to walk 10 miles on average per day but it was worth it.

On www.skyscanner.com check flights into Venice and out of Rome. You'll find that Naples is very inconvenient for flights, frustrating those of us who travel there frequently. Hotels on booking.com.

Thank you for all of your feedback. So I've a tentative schedule of what we would like to hopefully do. This travel is for the upcoming month of September. We want to minimize moving too many times. This will be a slow relaxing vacation for us so we are flexible with time.
Flying to Rome - hoping to take a train (depending on arrival time) to Florence on day of arrival
Florence (not sure what's best) - base in Florence or stay in one of the villages in Tuscany (rent a car if staying in village?) and do day trips to the Chianti region etc.
6 days in Florence/Tuscany area (meeting friends in Florence). Take a tour to the wineries?
Leave Florence to Naples/Sorento (train) to the Amalfi Coast (advise on where best to base) - 5-6 days in this area.
Then last leg of trip train to Rome - 6 days
Thank you

Would you clarify, as it seems, that you have return flights to Rome already and not open to flight alternatives?
September is still tourist high season so hotels and events will require reservations prior to arrival.
One time we stayed a week in the Valdarno region, which is the valley east of Tuscany. It worked well as a home base as we wanted to go to Sienna and hill towns south, but was close to a major town with a train station that we used to train into Florence or Pisa for the day. We did pick up the car in Florence, which was a pain as we arrived on a Sunday and there were no car offices open that day, so had to stay over, then avoid all the pedestrian only or restricted driving streets.
Personally, I would find it pretty exhausting to have to move on to a further town on day of arrival from overseas, but as you don't say how far you are flying to Rome, then it might not matter. There is also the fact that there are some trains from Rome airport to Florence making that an easier trip that having to go into Rome then on to Florence.
Otherwise, for a bare outline, it should work.

Maria - I have not made any flight reservations so I thought flying in and out Rome may be most convenient however I am open to suggestions. Thank you!

We just returned from our 2nd trip to Italy- we repeated Rome and Venice so I agree with above- don't skip Venice- we loved it just as much the second visit.

Our first trip was 17 nights.
we did this
Fly into Venice- 3 nights
Florence 3 nights
Tuscany/Umbria with car for 6 nights- stayed 2 Siena, 2 Montepulciano, 2 Assisi
Rome 5 nights- flew home from Rome

Open jaw (multi-city ) flights are often the better choice- saves you backtracking. Easier to fly INTO Venice than out of Venice.

This recent trip we did:
Fly to Rome 3 nights
Sorrento 4 nights- visited Pompeii and Capri
Amalfi 2 nights
Ravello 1 night
Salerno 2 nights- visited Paestum
Venice 2 nights- fly home

Still feel we should go back to Rome again for a few more nights- so much to see/do there!
One night stays are not usually our preference but in this case it worked out fine.

I agree w/ what was said above.

Rick Steves offers this itinerary: https://www.ricksteves.com/europe/italy/itinerary
It may be in his Italy guide book that he says:
x days: Rome
y days: Rome / Florence
etc., adding sights/cities w/ each increase in DAYS

After about the 8 day level, he says "spend more time in one of those cities"

At the least, look at flying to Florence and out from Rome.....even if not a direct flight.....Uness additional cost is considerably more. Avoiding train costs and transit hassles are worth something, however, and airport to downtown Florence is easier.

I think that what Roberto suggested is best and less hassle. If you have time however, I would add 1 more day in Venice, in two days to Rome and one in Florence.