Hi,
The Official Holidays in France link:
French National Holidays, Festivals, Religious Celebrations
Here is a link to Louvre:
Hours | Louvre Museum
Link to Eiffel Tower:
Opening time and last admissions
France is a Catholic country. Holy Thursday most probably the shops are open untill mid-day, Good Friday until Easter Sunday the shops are closed.
Try using google.com and you will find other places of your interest.
Hope this has helped you.
Eva