Do not get into an unmarked taxi. While public transport is the best (and cheapest) way to go, only get into taxis with a green lit-up sign on top (or call a ride-sharing service).
Art, food, culture. Paris has it all. You'll want to spend a day in Montmartre, visiting the old hangouts of famous artists and writers. But for a memorable meal, head to Boy on Rue Notre Dame de Lorette. This epic brunch spot sees a line snake down the block on weekends.