[Nyororin]

First question:
Do you speak fluent Japanese?
If the answer to that is no, then you are going to have a learning period during which you can pick up the language and culture.
I can't think of anything that is flat out insulting in Japan that is done in English speaking countries (assuming that is where you are from)... So unless you act like a jerk regularly, you likely will not end up doing anything incredibly offensive.

If you have the presence of mind to be observant of your surroundings and not be obnoxious when compared to everyone else (being loud and rowdy in public, for example) then you should be fine. No one is going to expect you to be proficient in the details, particularly not if you cannot speak the language... And by the time you have picked up the language you should be alright.