God expects Jews to follow the torah and gentiles to follow the Noachide laws. Until you've converted you're still a gentile and don't have additional heavenly obligations.
Perhaps you have heard of people in the process of conversion being required to do more. If so, it's likely a misunderstanding. Once you are studying with a rabbi he will guide you to take on more mitzvot in advance of conversion -- but that's not because you're obligated yet; it's because you need to learn to pray, keep kosher, keep Shabbat, and so on. In the same way, we teach children below the age of bar or bat mitzvah to do these things, not because they're (yet) obligated but because they will be and need to prepare. The instant you complete your conversion you'll be Jewish and fully obligated to the whole torah; that would be a bad time to start learning how to do it.