Anything. If you really want to learn, you can't learn by signing up for a class. You should like Japanese and watch it often. 1 Watch it for more than 2 hours every day for at least 5 days without class every week. I suggest you learn hiragana and katakana online first, which is the foundation, but you can see whether you want to learn it or not. It is estimated that half of the people who leave here have learned Japanese, and then find a free video to watch Unit 1. If you still have passion after studying, you can consider enrolling in class or online school.