Hey there, Kejiro
My advice for talking to Japanese people (and sorry if it doesn't help you at all, but perhaps you need to be more specific in the advice you need/seek?) is to first of all focus on the fact that they're
people and actually try to forget that they're from a certain country. In my experience, the majority of folk from most nationalities i've encountered are very forgiving of mistakes you might make in their language, and small mistakes in etiquette, too. They will greatly appreciate the efforts you
do make, but at the same time, as a non-native speaker, you aren't expected to be faultless in any way, and a lot of leeway will be given to you.
Just focus on communicating with people, as a human being, and the rest will follow perfectly naturally, I say.
Imho and experience, more can be communicated sometimes between folk with no common language by just a smile and simple gesture than by hours of fluent small-talk!
Good luck and please post back here with specifics (or sorry I missed them if you already did!)