One of the major issue that I consistently find with big cities is crowd and crowd related problems. Even as the city is still trying to get back to previous (before covid 19) normal, it was decently crowded.
However, during my short visit with family, I enjoyed following :-
a) Evening River tour :- cruising along the river and enjoying the Parisian architecture including Eiffel tower in a beautiful weather is truly mesmerising.
b) Night Bus tour :- They say Paris looks equally beautiful in night and day but I prefer the night.
c) Louvre Museum :- so much history and thousands of stories. Even a short guided tour, had lot to offer. Imagine the hidden secrets, Louvre for you, if you decide to spend more time time.