Judy (from another Judy),
Based on distances from one place to another in your plans, I would say that you should probably spread these out over the whole day one and plot it out to avoid backtracking.
e.g. Eiffel Tower walk-around (it's closest to your hotel, then across Pont Alexandre III, to Arc de Triomphe, then walk down Champs Elysees toward the Place de la Concord). By now it is getting close to lunchtime, so maybe find someplace to relax and enjoy being in the city while eating. It is still a long walk (for me) to Notre Dame, so maybe metro or bus? (Personally, I find the Champs Elysees too touristy with lots of fast food places and souvenir shops, so I would take the metro to the Notre Dame area from the Arc. If so, when you exit the metro near ND there will be lots of cafes and restaurants on the left bank close to Notre Dame.) Lunch, then the cathedral. After that, a short walk to Ste. Chappelle (a must-see IMO). After that you could head back to your hotel area (Rue Cler) to wander a bit and seek out a place for your light dinner.
I recommend getting a Paris street map to see the locations of the places you mentioned to efficiently plan your sightseeing without backtracking.
Day 2 (a Monday) does have lots of museum closures, but there is Montmartre and the Basilica Sacre Coeur, the Opera Garnier, the Invalides (Army Museum with Napoleon's tomb), the Galeries Lafayette (Blvd. Hausmann location), the Jardins de Luxembourg....and the Louvre. Take your pick. Oh yes, take a one hour boat ride on the Seine on Vedettes de Pont Neuf. Inexpensive, narrated, one of the best bargains in Paris! Sit up top for the best views, but dress accordingly. It will be cold in December. We go every time in Paris.
Have fun!
