Hello Joseph-charlesc,
You need to install the additional languages in your OS's Text To Speech (TTS) preferences. Acrobat/Reader uses the engines available on your system.
Note: Adobe Reader is a freeware application and it cannot translate English into French.
You may install the French version of Adobe Reader Adobe - Adobe Acrobat Reader DC Distribution
Also, refer to the following Adobe article to know more about how to change the language Can Adobe Reader read out loud in French/other languages?
Accessibility features, Adobe Acrobat Reader DC
Feel free to update this discussion for any further assistance.
Thanks,
Anand Sri.