From 50sounds,Hiragana letters and katakana letters (the Japanese syllabaries). Or Greetings, basic conversations such as Yes or No. It depends on what level you want to improve your Japanese. If you focus on conversation, you can do without studying hiragana katakana and kanji if you have a fairly simple conversation. However, if you want to be able to talk in Japanese about something, it's inefficient if you don't learn from the letters first. Good Luck.