Formal:
* Êtes-vous prêt(e) à apprendre le français? (Are you ready to learn French?)
* This is the most formal way to ask.
Informal:
* Tu es prêt(e) à apprendre le français? (Are you ready to learn French?)
* This is a more informal way to ask, suitable for friends or people you know well.
* Prêt(e) à apprendre le français? (Ready to learn French?)
* This is a very informal way to ask, often used with close friends.
You can also use the expression:
* Avez-vous envie d'apprendre le français? (Do you want to learn French?)
The best way to choose which phrase to use depends on the context and your relationship with the person you are speaking to.