When I booked tickets from Australia we had a hard time using the TGV/SNCF website. Since I was going to pickup tickets in France, we selected France as the country to pick them up in. If you do that, you get no language choice after that, French for you. It was quite a trial, including deciphering the confirmation that you need to take with you to pick up your tickets. Is there a better way?
If you want to get TGV tickets, the trick is to say you live in a non French speaking county (be aware Australia is not event listed), then you get a very good English website where you can pick seats etc. then when you go to the ticket machine to pick them up, don’t select “I want to pick up a ticket using my credit card that I used to book online”. Select “you want to pick up a ticket using a reference number” (you got it in the email confirmation). You still stick the credit card in, but this time it just works. Much easier.