How to get to Musée Pasteur by public transport?

Hello,
I will be visiting Paris for my first time (and just one day). I don't speak a single word french! I will arrive at the Airport Paris Charles de Gaulle Airport and I will have to travel to "Musée Pasteur". In the evening I will have to take my flight back at the Airport Orly...
Can anyone please tell me how to get to this location by public transport? Is there a website I can use to find out how to get to a specific place? Can you please recommend me some French sentences to learn so I can actually buy a ticket in the french language (or can I buy tickets at machines?). Any help is appreciated.