I went just a few weeks ago and thought it was way nicer than when I took DC ten years ago. Then it was smelly, dirty and SO rude. This time, friendly and way more relaxed. I lived there decades ago, in my twenties, and not a week went by without me being flashed at in some public place, and there were beggars without limbs on every metro platform. Both of those seem to have gone!.
OP, I'd go. Just think about the things you like most and do the Parisian version of them. For a first timer, I'd recommend a hotel near Opera or Boulevard Haussman as it is easy to get to from Gare du Nord if you are arriving on Eurostar. You can walk from there up to Montmartre, or take the funicular, see the city lit up at night, see the artists' square, Sacre Coeur, have a drink or dinner.
See some sights: Eiffel Tower or Notre Dame and Ste Chappelle, or one of the galleries - I prefer Musee d'Orsay to Louvre, as it has the best Van Goghs and Monets. Then just chill a bit - boat trip, parks, markets and food halls, cafés in the Marais, shopping.
You can see a lot in a few days.