Studying Japanese Roadmap and Supplemental Materials

Once you finish Genki I, and you’re working your way through Genki II, be sure to check out the Absolute Beginner Book Club.

Once you’re learned some grammar, you’re going to need to find a way to get better at recognizing it. This can be done via consumption (reading, listening) or production (writing, speaking). The ABBC is a great way to cement some grammar via reading, as you’re in an environment where you can read along with others and ask questions along the way.

I suppose it depends on how strictly you define “idiom”. An idiom is a collection of words that together have a meaning you can’t deduce from the words alone. For this reason, I imagine it’s very unlikely that any idioms would be shared by languages as different as English and Japanese. (But if anyone knows of any, it’d be interesting to find out!)