We (family of 4, kids ages 11 and 17) just returned from 4 nights in Paris (June 30 - July 4). I've been to Paris more times than I can remember and this trip was all about meeting up with family visiting from the US. I also speak French, which helps.
As I received good advice from other contributors, I thought I would share some details from our visit.
Air Transportation - we arrived on an Austrian flight from Vienna and returned to Vienna also on Austrian. Slight delays on both flights, but nothing significant. Security at VIE and CDG was quick and efficient.
Ground Transportation - upon arrival at CDG in Terminal 2, we went directly to the train ticket office and purchased our Navigo Decouverte passes which were valid through Sunday. We brought our own passport photos. The line took us about 20 minutes. We used our Navigo passes a lot - on buses, the metro, RER trains, to/from CDG and to/from Versailles. Very efficient/easy to use the card, saved us a lot of money. I used Google Maps for figuring out best routes for public transportation.
Hotel - we stayed at an Ibis Styles near Gare de Lyon. Very happy with the location as there were many good restaurants in the area north and west.
COVID - We didn't wear a mask at any point during our trip. On public transportation, there would be a handful of people wearing a variety of masks. Same in museums, restaurants, grocery stores and other attractions. No one ever checked for any COVID documentation.
Safety/Security - I felt totally safe the whole time. None of the "scams" you see mentioned here all the time. I carried my usual old backpack and typically had my iphone in my hand.
What we did - Note - we bought the Paris Museum Pass for 4 days online. Arrival day was late, so just had dinner near our hotel.
Day 1 (Friday), we went to the Paris Saint-Germain football stadium for the tour. Pretty cool experience if you are a big football fan (I am not but it was fun). We didn't have reservations which wasn't a problem. The tour is at your own pace and you see the locker rooms and club areas as well as the field and stands. After PSG, we had lunch nearby and then went to Sainte Chapelle (skipped the line), then the Louvre (we walked in with just a few minutes wait and did not have a reserved time slot). We had dinner on Rue Montorgueil followed by the 9 pm boat tour with Vedettes Pont Neuf (bought tix online in advance). That was a big day, not sure how we did all that but we did.
Day 2 half of our group did the Eiffel Tower with a hugely expensive tour as regular tix had sold out. They went all the way to the top. The other half of the group went to the Marché d'Aligre. Met up at Musee D'Orsay. Went on a pastry buying frenzy, stopping at Ble Sucre, Boulangerie Bo, Georges Larnicol, Stohrer and other places, so had a dessert buffet with the entire group in our hotel lobby after dinner at a random Bistrot.
Day 3 half the group went ahead to Versailles on a package tour full of bicycle riding through the garden, including stopping at the market for picnic provisions. They loved it. My half of the group spent the morning laying in the grass at Place des Vosges followed by a stop at the Galeries Lafayette at Haussmann. We then went to Versailles to meet the other half of the group for the tour of the interior. We had reserved a time slot. I guess it is worth it for the Hall of Mirrors, but how many bedrooms can one see? There were a group of theater students from the Sorbonne in period costumes performing in many rooms inside which made it interesting and great for photos. We had Lebanese food for dinner.
Day 4 - walked through Place de la Concorde just because and headed to Napoleon's tomb. On the way we walked past the Rodin Museum which was paparazzi central as Dior was about to start their Paris Fashion Week show. We hung out by the photographers and saw some famous people I think.