Thank you for all the help!
Here is my full itinerary, any advice would be appreciated. I am a first time traveler and flyer.
(3 nights Florence, 3 nights Venice, 2 nights in the Dolomites)
✅internationals drivers permit
✅passport being expedited
✅printer all travel documents
✅removed pizza & gelato class that was scheduled July 18 (arrival date) at 3pm to allow time to rest but not sleep.
✅Changed flights to have better layover time (previously had 1 hour at Paris airport layover
July 17th - depart from airport 11:30am to Atlanta Georgia. with a 2.5 hour layover in my home country (USA) to Rome, Italy airport. (Bringing a personal, carryon, and mostly empty checked bag to bring back goodies. I booked business class train tickets so I have the space)
July 18 - arrive at Rome 8:15am take a train (booked 1st class) 10:30am-12:46pm from Rome to Florence. Check in hotel and allow rest of the day to relax, enjoy foods and sleep early about 8/9pm.
July 19 - see accedemia, uffizi, and duomo first half of the day. (Beginning 8:30, Ending about 3pm with rest in between) Relax and enjoy the rest of the day until visiting a restaurant to have a sit down dinner around 7:30pm.
July 20 - day trip to cinque terre. Wake up early around 6am and hop on the first train available to la spezia. Spend the entire day swimming, relaxing and eating (I do not care to visit all the villages, I just want to see a beach for the first time)
Take train back home. Luckily my hotel is right near the Florence train station.
July 21 - spend the morning (wake up - about 2/3ish) last moments in Florence. Take a 2 hr train to Venice from Florence. I booked business class tickets. Spend last half of the day from 3ish to the end of the night settling in my hotel, enjoying Venice. My hotel is in the actual Venice island off the canal.
July 22- gondola ride in the morning, enjoy the day exploring Venice.
July 23 - visit st marks square, doge’s palace, and st marks basilica. Eat and enjoy.
July 24 - pickup rental car 8am at Marco Polo airport, head to my hotel at cortina d’ampezzo. Arrive around 10:30ish roughly (accounting for any extra time getting the rental car & stops) , and spend the rest of the day exploring nearby and sight seeing some local mountain areas. (I may possibly book a half-day fishing guide for this evening)
July 25 - head to lago de braies early. Explore and hike, and then head to Tri Cime de lavaredo. Explore & hike. Head back to hotel toward the evening and enjoy food & relax.
July 26 - head to Marco Polo airport to return my rental car by 8am and depart from the airport at 11:05am. 3 hour Layover in Atlanta Georgia. To my home / city airport.