You have three ways to get from Nürnberg to Paris:
Flying
Taking the train
Driving

You have to decide yourself what you want.

Discounts for 1st clas are available but to be honest 2nd class on Geman trains especially ICEs are good enough. Just make sure you have seat reservations (when you buy the train tickets you will be asked if you want seat reservations or not) Seat reservations are not mandatory but recommended.