I'm guessing your tickets for Paris to Bordeaux are iDTGV tickets since you printed them yourself.
There are no other hoops to jump through. When you arrive at
Gare Montparnasse to take your train, there will likely be SNCF employees with handheld bar code scanners along your train's platform. They'll scan the barcode that's on your ticket, then let you pass. (So keep the ticket uncrumpled for easy scanning).
That's about it. Have a great trip.
Ben