I'm a bit confused about public transportation as we never use it where we're from. If we get on the Notre Dame Station, will this travel straight to Versailles? So we won't need to get on another train or metro? Thanks so much!
There is a RER C train from Paris Notre Dame station going to Versailles Chateau Rive Gauche, that is the train you want to take to get to Versailles. There are no connections to make; It is a direct train from Paris to Versailles. Just be sure to only board trains that show Versailles Chateau Rive Gauche (shown as Versailles Chateau RG on some displays). As there are many RER C trains going to different destinations from the same train station & platform.