How to get from the airport to the center of Paris
Here it all depends on where you are arriving. There are three options (Le Bourget does not count): Charles de Gaulle Airport (Roissy-Charles de Gaulle) is the largest airport where most international flights arrive; Orly is mainly for domestic flights; Beauvais is a low-cost airport.
From Charles de Gaulle airport to Paris
The easiest and most budget-friendly option is suburban trains (RER)+metro, so we will tell you about this method. When you arrive at the airport, just follow the signs "Paris par train" - they will lead you to the station. You need line B. Don't get it mixed up, or you'll end up somewhere in Lille or Bordeaux (which, by the way, is not such a bad idea). When you arrive at the station, you will see ticket vending machines - that's what you need. Tickets cost €11.4.
From the airport, you need to go to a station where you can transfer to the metro. The nearest one is Gare du Nord. You transfer and go on to the place you are interested in.
Travel time from the airport to Gare du Nord is approximately 40-50 minutes. The trains run approximately every 12 minutes from 4:56 to 23:40.