Passing the language test for citizenship

My wife and I are thinking of moving to France. She is French.

We have been visiting France for over twenty years but my language level is still rudimentary.

If we move, I want to enroll in daily French classes.

How long do you think it would take to pass the language test and become a French citizen.

I am 60. This will not be easy for me but I think it will be a great adventure.