Hello!
I did read through the tutorial posted, but I'm rushing like crazy, we leave on Sunday for Paris!

If I book the idtgv train from Paris to Avignon, for 2 adults and 1 infant, on the checkout page it only shows the 2 adult fares.
I do realize that our child can travel free without a seat, which is what we are going to do, but even though I selected 3 travellers it still doesn't show up on the checkout page... (just thought that it might for reference?)
Is it fine to purchase and print them up like that? Will I have any issues bringing on our son?

If the child is young enough to travel free, then I wouldn't worry about it.

If there's no ticket associated with the kid, there'll be no issue. Don't worry.

thank you!

Just to clarify, you child must be under 4 years of age to travel for free. If he is, no ticket is required nor is one issued.