I've been to Europe a number of times over the past 50 years. CDG was most recently in 2018. Too old to be of any use to you for this trip. However, there have been some suggestions that I agree with completely.
Get Global Entry. It will save you time coming back into the US. And as I have over 1.4 million miles on UA I've seen my checked luggage show up quickly after getting to the carrousel after clearing immigration using GE, so that delay may not be so bad.
Sign up for the airline's frequent flyer program. It can be very useful to you. As a Million Miler with UA I am, at a minimum, Premier Gold for life, as is my wife. I book E+ seats as soon as I purchase the tickets. The extra legroom is worth the no extra cost to me.
Give yourself plenty of time for connections. 2 hours at a minimum if possible. As noted, if your first flight is running a little late, you'll be glad for the extra time. On the other hand, UA has put us up for the night, along with dinner and breakfast vouchers, when we did not make the connection (and it was due to weather!). We arrived in Sydney the next day and I missed the 1st half day of meetings, but it could have been much worse. A membership in their Mileage Plus program worked well for us. Then there was that trip home from CDG in 2018. That worked out extremely well for us. Too long for here, but again membership came through.