First you have to do the episodes/quests. I have attached a walkthrough. It will help with them.
After the basingse mall reopened, you can send Korra to LGBT (to Kuvira) to get her in obedience and morality classes.
Then you can test her with night time events in her room. cooking handjob etc
Then at morning you can actually train her in through spiritual, physical, and mental lessons.
After you complete all these things, you can train her Chakra lessons