Could anyone recommend the best train system to get from Salzburg to Paris? Thanks so much!
Look up connections at the site of the austrian railways, www.oebb.at.
In principle, there are two options, either going with the austrian Railjet to Zürich and transfer to the french TVG, overall travel time approx 10 hours, or going across southern Germany with two transfers (Munich and Mannheim or Stuttgart, approx. 8 hours. The Oebb site will show you both.
BTW, if you have an Austria&Switzerland rail pass, you will want to avoid the train through Germany.
This is a route I would do by day train. I would take the train Salzburg to Munich, then Munich to Frankfurt on the ICE direct, then the TGV or ICE direct to Paris Est before 1700 hrs.