First time in France

I think 7 days is a good introduction to Paris. You would have time to vary the experience with a day trip to a small town in the region or chateau -- there are literally dozens of cool places reached by local train. And Reims if a Champagne house cellar tour interested you is only 45 minutes away by TGV.

Normandy is a good ways away and needs a few nights -- and with so little time, I'd slow town and explore Paris. If your 7 days falls in a week i.e. more or less Monday to Sunday, you could get a Navigo decouverte travel pass that would let you travel anywehre in the Ile de France for 30 Euro for the week-- one of the great travel bargains in Europe even with recent price increase. (I just spent a week in Berlin and the price for a similar transport pass was about 50 Euro for the week)

You can see some examples of day trips we have done here: (and there are many more I haven't written about)
https://janettravels.wordpress.com/category/day-trips-from-paris/
On the same site you can see some of the things we enjoy around Paris --

Whenever you go to a new place it is a bit overwhelming and you get sort of hammered by logistics -- by taking a little more time, you are more likely to feel at home and really enjoy the process rather than ticking off a list of things in a rush. So much of the pleasure of travel is the serendipitous.

Well, the Seine is the watery heart of Paris and there are several styles of boat tours. Some years there have been fake beaches for sunbathing, not very convincing with traffic whipping past nearby. But with regional attractions such as Versailles to provide variety, I'd have no trouble enjoying the city for a week even after my two dozen visits.
Paris is a little more relaxed in August as some residents take their month of vacation elsewhere. Some restaurants may be closed but plenty more will be open. The month has been steamy-hot in recent years so a hotel with air conditioning could be a relief. After all, the secret to appreciating such a famous metropolis is to take it easy.

How wonderful for you two! Yes, Paris is an enormous city, but there are so many parks and little streets where you feel like you're in a village. The key is to make sure you explore beyond just the big tourist spots, and maybe decide to get lost (sort of) by wandering around smaller, less busy streets. Agreed that August will be a bit quieter. I'd vote for a week just in Paris.

I think a week in Paris would be wonderful. A couple of day trips I’d suggest are Giverny and Chartres.

My first instinct was to encourage your Paris-Normandy plan, or something like it, for a taste of France outside Paris. But the other posters encouraged me to change my thinking. Unless you really hate big cities, a week based in Paris would give you a chance to explore not only the "main" sights but some of the neighborhoods and day-trip destinations like those mentioned above. Crowds won't be as much of a problem in August as in other months, though many of the people you'll encounter will be non-French tourists like you. Air conditioning will be a definite plus in a hotel.

Paris has some amazing parks -- Luxembourg Gardens, Parc Monceau, Jardin des Plantes, Bois de Boulogne, Bois de Vincennes. In the last two you can feel completely away from the city. You might also consider one of the longer boat cruises offered by Canauxrama, on the Seine or the Marne, for a water experience.

Hello,
I envy you.

Don't feel seven days is too much for Paris. If you must get away for a night, Chartres is a quick train ride and Madame Sylvie Menard runs a wonderful, truly French bed and breakfast, Les Conviv Hôtes. Her English is embarrassingly good.

Seven days will allow you to buy Baguette sandwiches and some juice, go to the Luxembourg Gardens and enjoy a French lunch out of doors. Another day you could stroll through the Bois de Boulogne while also visiting the art at Musee Marmottan Monet.
A meal in the Marais, one of the remaining medieval areas of central Paris. Oh, and a morning breakfast at Cafe Hugo in the Place de Vosges then a visit to the museum of Victor Hugo in the same square. The Picasso Museum is nearby and then you are in the Marais again. Gosh a slow stroll down Rue Saint. Denis with all the lovely shops and places to stop for a drink or snack.

Musee de l'Orangerie and the d'Orsay are across the river from each other. These are fairly centrally located, go in when the line is short. No sense wasting Paris time standing in line. At l'Orangerie you are in the Tuileries another good place for a stroll and maybe a bite to eat.

You could also go in search of this year's winner of the best baguette in Paris competition. It is "Au Levain des Pyrénées" 44 rue des Pyrénées.

An evening cruise down the Seine and back. Some offer a meal, some don't. We were too busy looking at Paris lights from the boat we couldn't have enjoyed a meal.

So much to do don't try to do too much in a day. An afternoon nap in the heat of the day to give your feet a rest is always a good idea. Remember, you are here to look into each other's eyes and say, "We are in Paris".

wayne iNWI

I'll provide the counter argument. I've been to Paris about 5 times. I LOVE it. However, I've never stayed more than 5 days, usually less. I've explored it bit by bit. I've found myself back there often because its a city that I can usually fly to relatively inexpensively and nonstop so I can use it as the start of a number of trips.

Normandy is an interesting and beautiful place to visit. I would not day trip to Normandy. It is too far and there is too much to do.

Given your inclination to be overwhelmed with crowds/cities, Normandy may be a nice break for a few days.

If you enjoy your trip, you may find yourself wanting to visit Alsace or Loire or Brittany or Dordogne, etc., all those areas can be done by flying into Paris, spending a few days and then heading to other areas via train.

I like your original plan unless you BOTH are really into art museums. I will be making my 4th visit this year ( wife’s second ) and I am struggling to find things to do !

With this in mind: "We both get a little overwhelmed with crowds and cities and were looking forward to being by the water,"
I think that your initial plan of 4+3 is perfect. 4 days is a good amount of time for a "Paris highlights" visit (without Versailles).
You do need to be in Paris the night before your flight home, too.

Maybe do Normandy at the start of your trip? You could take a train to Rouen or Bayeaux upon arrival to CDG

Yes, you can do Paris and Normandie in a 4-3 plan and yes, that could be overwhelming. You could even do 4 days in Normandie and 3 days in Paris if that fits your interests. It may not be what others would do, but it's your trip.
This is your first trip to France, but use the other trips you've made as a reference. Do you tend to overplan and end up feeling rushed? Are you comfortable with prioritizing your "must-see's" and letting go if one or more don't fit in real time? How much travel you can tolerate in a day ("getting there" versus "being there")? I think you should allow for travel times being longer that what it says on line, just as you would allow for unexpected expenses.
Please heed balso's reminder about being in Paris (or at the airport) the night before you leave. But I don't think that necessarily means doing Normadie first, Paris second. You might not want to end your trip in Paris since you both get a little overwhelmed with crowds and cities.
I hope you have a wonderful time.

I have nothing to add re: the original question, but I want to chime in to second Balso’s suggestion regarding being in Paris the night before flying back.

My family has made this our standard travel procedure: fly into and out of the big city, spend a few days in the big city, goother places, then spend the last night in the big city and goto the airport the next morning. For example, this fall we’re doing Paris to Gordes to Lyon to Paris.

Spending the last night in the big city allows us to check off anything we missed, or allows us to shop the last night so we don’t have to carry stuff around the whole time.

PLUS it’s easier to get to the airport from the city than from somewhere outside of the city.

I would absolutely be in Paris the night before your flight (I do this for most any city) which was why I recommended going to Normandy at the start of the trip. Otherwise you would be changing hotels twice instead of once. Also, I find a train ride after arrival gives me an opportunity to take a short nap so that I can function until bedtime on that first day.

Seven days, stay in Paris, there is much to see there.

Like you, I can become weary of a big city. I love Paris, but I also need a break. How about taking a day trip midweek to Reims for the champagne caves, or to Giverny? There are many wonderful sights that are doable by train from Paris and back in time for dinner. Even closer, we really enjoyed our visits to Chantilly and to the Air and Space Museum at Le Bourget, and both were much less crowded and hectic than central Paris in August. Have fun!

We did a 2 week London and Paris trip in 2019. For our Paris portion at the end we did 2 nights at Disneyland Paris but the rest of the time before it saw the sights in Paris and spent one day at Versailles.

On our first trip to France we spent 1 night near Giverny, 5 in Normandy, and 9 nights in Paris. Much as we loved Normandy, with only a week I would stay in Paris and take one or two day trips. However, if big cities really do overwhelm you, your 3/4 night plan would be fine too.

Sent a PM to you.

My advice is to consider how experienced you are with travel (or how willing to struggle through). I definitely would not try to get from Normandy to Paris to catch a flight. No way! Staying the night in Paris before departure is a must.

Getting to Normandy from Paris CDG is doable if you arrive in the early morning, are comfortable navigating the metro (with luggage), and getting to Gare St. Lazare to get on the right train. If you're not seasoned travelers, you may end up falling short and missing the last train to your Normandy destination. We are seasoned Paris visitors, and we nearly missed our last chance train in 2022 due to many delays (disembarking, customs, baggage claim, etc).

As much as I love Normandy and D-Day beaches, I think trying to do Rouen, D-Day, Bayeux in those few days is pushing it. I'm not a huge Rouen fan, anyway. You might decide to just do Bayeux for a couple of days, or just spend it all in Paris with just 1-2 agenda items per day and not be so rushed. I highly recommend the Fat Tire Night Bike Tour in Paris.