Visiting a new country can be quite intimidating especially when you don't know the language. And thinking of how to get from point A to point B can be a headache when you don't want to spend a fortune. JDL and I always try to learn the country's metro if they have, it saves money, time and gives you a glimpse of how the locals travel.
Upon arriving in Paris, a lot of people opt for car service or taxi because it's so convenient and easy. But it also cost the most. A ride from Charles de Gaulle Airport to the central of Paris can be roughly 50-80 euros (60-100 usd). There's also the bus option which is the cheapest, around 10 euros but only drops you off at certain stations. JDL and I stuck to the train system Paris offered.
If you're traveling to Paris for the first time like I was, this will definitely be useful.
First thing first, there's basically 2 main train systems in Paris. The regular Metro and the RER. The RER is more of a rail (like NYC's LIRR or metronorth) whereas the metro takes you around central Paris. The metro is color and number coded while the RER is color and letter coded. There are 14 main metro lines and 5 main RER lines.
So with that said...
We landed in Terminal 1 at the airport and needed to take the train which was in Terminal 3. Once we've gotten our luggage and headed towards the "exit" we saw signs of where to take the train, it's fairly easy at that point, just follow the directions on the signs. Once we arrived at the "station" we saw ticket vending machines. As Americans, our credit cards did not work so we had to wait on line to buy the tickets from the teller. Language was not a problem here since the tellers were probably approached by many foreigners. The tickets to Central Paris was roughly 9.75 euros per person and the teller even told us which platform it was on. From then on, it was simple. Just wait for the train, hop on and get off at your destination.
The trains and stations are very clean in Paris. Trains can be a bit cramped but the stations are extremely clean. A neat little tid bit I found was when hopping on or off the train, notice the doors. Some have buttons or latches which you need to press or lift in order for the doors to open, while others just open automatically.
Paris is split up into different zones and not any boarding ticket can let you go to whichever zone you want. The regular metro tickets can get you anywhere from zone 1-3 which is basically central Paris. Lets say you want to go to the Palace of Versailles, you can't just use a regular metro ticket, you would have to buy the RER ticket instead which cost a bit more but lets you go to zone 4 which is where the palace is.
Let me put it this way. If you were planning to go Versailles, don't try to buy your tickets in advance because the cost of the ticket is different from each station (the price is determined from the distance of travel hence the price difference from each station). If you know which station you are leaving from, then go ahead and use the machine to purchase your ticket from that station. You can enter your destination into the machine and it will calculate the amount you need to pay and spit out a ticket for you. For the rail aka RER, remember to not throw the tickets away after using it to go through the turnstile, you might just need it to exit the platform later.
A very useful website which I had use prior to the trip is from Feels Like Home In Paris.