This website walks you through most of the common ways to install a Japanese keyboard on your device.
Genki Goals:
If aiming for level 2, aim to get comfortable with chapters 1-3
If aiming for level 3, aim to get comfortable with chapters 1-6
The the link on the left helps you check your knowledge, the video above helps clarifying everything from the textbook. Use both to help you navigate the Genki textbook at your own pace.