I understand forming the past tense like 'I have not been' but I'm unsure as to how to phrase this as it is something that was true but now is not. If that makes sense. It's the 'had' part that's confusing me. If anyone could clear this up I would be very grateful. Thanks.
Edit: my attempt, as I understand past perfect does not exist in Japanese I tried to do something that would be in English (roughly) 'before last year, I have not gone to America'.
Mae ni kyonen watashi wa Amerika ni ikimasen deshita.
まえ に 去年 私は アメリカ に いきませんでした。
However I don't really know if this is correct (and if I'm missing a particle after kyonen?)