Rail Europe Prices

Cheapest and best way of travelling between paris and Swiss, in paris, in Swiss?
I am planning on a 3 day visit in paris and 3 day in siwtzerland. I going to Interlaken, Bern in Switzerland. In paris I would be going to most of the tourist places. Which is the best and cheapest way to commute. I see a lot about RailEurope would that be helpfull or is there a better alternative. Is there a one time pass which i could use for all my commute.
If i get a raileurope pass, would i be eligible to travel in paris, in swiss and also between paris and swiss.
Is paris metro different from rail europe? does rail europe go to all tourist places in paris
How much would car renting and insurance cost for 6 days. What’s the gas price? would it be cost effective?
Hello, I had this trip many times from Paris to Belgium, Holland, Switzerland and Germany by train. Take a train ticket please..it is both fast and not so costly.Youw ill enjoy the scenery so much. Bon voyage…Good luck..
PS: metro system works in the city. Trains in Europe are very fast and take you all around Europe…The gas prices in Europe are more expensive than those in the US so if you are going alone, do not rent a car..if you are with a group, then it might be a good alternative.