If you got to Rome, I highly recommend staying in Trastevere! It is where I stayed when I studied abroad and where my mom and I stayed on our trip. It is less touristy in my opinion, with great food, amazing produce markets, and cute cobblestone streets. I have so many other recs if you decide to go here!
There is a reason why Lake Como has been blowing up on social media over the last few years! It is absolutely breathtaking. The most popular towns are Bellagio, Varenna, and Menaggio, but if you are looking to avoid the crowds at least where you are staying, I highly recommend this airbnb linked in Sala Comacina. My mom and I stayed with Wendy and had the time of our lives. Sala Comacina is much smaller with only a couple restaurants and the local bar, but Wendy knows everyone! Tell her my mom and I say hi and to give you the experience we had :) The only potential downside is there are less ferry options each day, but it was still totally doable - just meant less flexibility of our schedule.
Usually when you go to the South of France you pick a place as your "home base" and travel around from there - everything is just a short train ride away. Most people pick Nice, but this is where we stayed and we absolutely loved it! It is also where we got engaged :) It's much smaller but so cute and quaint. The beach is in the bay. It is not the best beach in the world but far less crowded than those in Nice. We spent basically every afternoon and evening on that beach.
We did a tour of this villa (https://www.villa-ephrussi.com/en), and we thought it was fun and worth it! Then we rented chairs at this beach club and just hung out all day, got food and drinks. It was one of our favorite days!
Antibes was our favorite bigger town and has some of the best beaches. It was crowded but nice sand vs. being rocky like others in the region. We went to Plage de Ponteil. We ate dinner at Nacional Trattoria, and it was sooo good. We walked to it from that beach - it was such a beautiful walk. We wish we would have spent more time in Antibes.
If you like more of the remote, adventure-type vacation, Evan and I really enjoyed Corsica. It kind of reminded us of driving around Maui, but hotter, drier, and even less built out. But that meant we got to explore some of the coolest wild beaches! We flew in to Bonifacio, rented a car, and stayed near Porto-Vecchio. We ate at this restaurant linked twice because it was that good! All of our favorite beaches required a bit of a walk/hike to get to them, but it was worth it to avoid the crowds! Our favorites were: