Does one of your 3 days include your arrival day after your overnight flight from Canada? Four nights, right?
It will help to know when you are traveling as well.
For myself, I’d not spend the time on Versailles but you might choose to do so. The last time I went I spent a full day there and didn’t get thru all of the garden area. I left Paris on the RER train about 9 and returned about 7. If you just do the Palace it will take more than 1/2 a day.
As indicated there are tours of the Louvre you can sign up for at the museum. A walking tour company, Paris Walks, also does tours if their times coincide with the days you’re be there.
www.paris-walks.com