Am I able to buy an EZpass for French toll roads before I leave home?
EZPass does not work in France. I am pretty sure that you need an EU bank account to get its equivalent (a Liber-t pass). Or at least you did as of last summer.
We bought the Liber-T, like an easy pass, at the first toll plaza we came upon leaving Paris. Just park and go into the building.. It’s connected to our Amex card. That’s all we needed.
Here's the web site for Liber-T: https://www.telepeagepourtous.fr/fr/particulier/toutes_nos_offres/formule_balade
I remember looking into it a couple of years ago, but didn't think it made sense for me. I also don't think you can get it delivered before you arrive in France. The way Bets did it is probably the easiest.