If it’s a day, I’d say avoid the Louvre, it’s massive
Musee d’Orsay is nice, Grande Palais, Pont Alexandre III, Place de la Concorde, Sainte Chapelle is much nicer than Notre Dame, although they are very close to each other so could do both. Probably not enough time for going up the Eiffel tower, Palais de Chaillot is a good viewing point for looking at the tower though
Paris isn’t a dump, there are ‘interesting’ parts, but it’s a lot cleaner than most of our cities