I went there a few years ago except I forgot most of the places I went to. Okay, now to tell you the few that I actually remember
1. Notre Dame
not sure if it's open because I went there like a week before it burned down, but it's really pretty
2. The Cemetery (Panthéon)
there's a cemetery with a bunch of famous people. It's the one with Marie Curie in it but I'm pretty sure there's another one with famous ppl also.
3. a bunch of random museums (ex. the Musée Picasso, Musée Marmottan Monet, The Orangerie)
. a. pablo picasso, (just a bunch of his work)
. b. Musee marmottan monet (his work too but there are those famous water lilies)
. c. the orangerie (more water lilies except I think this one is better than the one before, b)
Now, for the places I probably went to
except don't remember 
I definitely went there
1. Musée d’Orsay
one of the largest museams in Europe, it has mainly french art
2. Tuileries Garden
it's right next to the louvre so you can go there after you go to the museum for a lunch break or smth, idk-
it has a french design
3. Panthéon
haha I just found out what that weird cemetery was called-
4. Centre Georges Pompidou
yes yes yes and yes (a modern art place with modern architecture GO THERE)
5. Le Marais
some pretty medieval street place (apparently) I didn't go there btw (at least I don't think)
6. Versailles Palace
GO it is ranked like top, and it's so pretty I've been there (like everything else except for number 5)
7. Catacombs of Paris
some really nice cemetery, it's cool though, has a lot of bones
8. Galeries Lafayette
w i n d o w s h o p p i n g
9. Palais Garnier
opera house and stage of some of the most famous acts in paris