Whatever is your location in France , look for AirBnB for one month. That would be most reasonable.
In month you can cover France , Amsterdam , Belgium and Switzerland . In this part of Europe no one country is quite far away from other and the public transport is super efficient
so plans your weekend and enjoy your stay !!
Well i doubt anyone would be able to give you a 1 month itinerary for France.It seems you are going there for some work and would like to travel France during your time.
Usually 4 - 5 days at max should be sufficient if you just want to visit Paris.You can go through my itinerary to see the places to visit in Paris and add the following if you are interested:-
3)Orsay Museum https://www.tripoto.com/trip/3-countries-3-cities-of-europe-in-1-lakh-per-person-5a00a5f952bdc Additionally if you have time,would suggest to visit Monaco/ French Riveira which is a very beautiful country very close to France.It is the mediterranean coast of Southeastern france.