help with sights to see

I would watch Rick's videos on Italy which cover all the top attractions in Rome and Florence including daytrips and take notes. You can watch those for free on the web via the link below. Also you can get a guide book at the public library to take out or buy one in electronic format. All the star attractions are listed in the guidebooks

https://www.ricksteves.com/watch-read-listen/video/tv-show

Also here is a year worth of answers from the forum related to must sees in Rome:
https://search.ricksteves.com/?button=&date_range=2y&filter=Travel+Forum&query=Must+see+rome&utf8=✓
Florence:
https://search.ricksteves.com/?button=&date_range=1y&filter=Travel+Forum&query=Must+see+Florence&utf8=✓

I can help with Rome. It's been awhile since I have been to Florence. Must-do is in the eye of the beholder, but here are what I consider some of the essentials in Rome. A lot of these have longer lines, with a short visit you want to either book tours, book tickets ahead yourself, or figure out other ways to limit lines (buying ticket at different sight, going super early, etc). Rick Steves books go into this.

-The Pantheon!!!
-Colosseum and Forum.
-Walking around the historic center (Pantheon/Trevi/Piazza Navona/Campo di Fiori), perhaps in the evening after dinner (nicely lit up)
-Vatican. St. Peters and the museum. This is a good place for a skip the line tour. The word "crowds" doesn't even cover it, it is extremely popular for obvious reason.
-if you are Catholic or love church architecture/design/art then going to some of the famous churches is a must. San Giovanni in Laterano, Maria Maggiore, Peter in Chains, etc. There are more than you can see, pick based on location or a particular artistic or historical feature of interest to you. I personally liked San Clemente because you could go to the excavations under it and see layers of history.
-eat gelato and cacio e pepe!

Museums - you won't get to all but here are two that I love, know that there are others
-Borghese Gallery - amazing sculptures, not crowded because you HAVE to book ahead and they limit the number of tickets sold
-Capitoline Museum - best ancient Roman art and artifacts, also the lower level has great views of the Forum.

Anita, I'm going to link one of your previous threads that may be helpful to responders:

https://community.ricksteves.com/travel-forum/italy/best-tours-for-sightseeing

The fact that you'll be moving 10-12 people around - and from a villa which likely requires either vehicle rentals or drivers - is significant as advance ticketing is almost a necessity at some attractions to avoid long lines. Also this:

My family and are will be going to Italy in June for 10 days. We will
spend the first 2 days in Rome....

If those 2 days/2 nights include arrival day, you only have one FULL day to spend in Rome. Arrival days are always partials, and often jet-lagged fogs at that so getting 10-12 people settled in a foreign city will likely be all that can be accomplished on that day. What to see/do in one FULL day depends on the make-up of your group: ages, interests and any mobility challenges taken into consideration. Young children and/or seniors who can only spend so much time of their feet will limit how much ground you can cover, and ANY group is only going to move as fast as the slowest member.

The #1 and #2 most-visited attractions in Rome are the Colosseum and the Vatican Museums. Advance tickets are a necessity to avoid long ticket lines, and one or both of them will involve booking a specific entry times. Both of these attractions will also be mobbed so doing them both in 1 day would be exhausting for even the heartiest traveler, even with a comprehensive tour.

Must-do attractions in Florence depend on what one is interested in. How many day trips are you planning into Florence, and are you planning on everyone doing everything together? Same as Rome, the several top attractions - the Uffizi, for instance - require advanced, time-entry booking to avoid the longest lines. Then again, if one doesn't care for art museums then it's not a must-see. Same for the Vatican Museums in Rome.

Long story short, it's less about what anyone else thinks is a cannot-miss but what's the best fit for your group, their interests and abilities. What can you tell us about the makeup of yours and their interests, and are you expecting to make a sightseeing itinerary just for YOU or for everyone?

possibly one more day at the end in Rome.

If you are flying both in and out of Rome then yes, you'll want to spend the night before departure in Rome. In fact, it would be more efficient to go directly to the villa near Florence on arrival day and put all of the time in Rome (3 nights/2.5 days) at the end of the trip.

We were just there for the first time. I would want two complete days in Rome. We had that plus 3-11pm the day we arrived (Mon - Thur) and it felt right. I could have spent another full day simply sipping Rose and gazing at the Forum and Colosseum. The day we arrived we began by taking Rick's "Heart of Rome" walk from Campo di Fiori to the Spanish Steps, with many stops and a dinner. It was a great way to acquaint ourselves with many parts of the city. A walk about and dinner in Trastevere is a must, as well. (Tonnarello was great with delicious food!)

In Florence you'll need to decide how many hours you want to spend in museums versus walking about, especially if it's an hour drive or so from where you are sleeping. Again, spread over 2.5 days, we enjoyed seeing David for maybe an hour total, spent a few hours in the Uffizi and a couple at Pitti Palace. All good. Loved Piazzale Michelangelo and visited one morning and once for sunset. Also, Rick's Florence walk was taken and enjoyed.

Thank you all.