Trains from Orly Airport

Hello all,

I am in a bit of a pickle. I need to get from Orly airport to DUROC metro station where family friends are going to collect me. How would I go about doing this? Any advice would be greatly appreciated.

Also, does anybody have any suggestions for activities/sightseeing in Paris which are not too expensive? I am interested in history, architecture, museums and all that nerdy stuff.

I would love to go on a day trip to Versailles to see the palace. Is it easy to get there by public transport?

Happy travels to all!

Gappie