YOU SAID:

i got on the train last night i don't know where it's taking me

INTO JAPANESE

昨夜電車に乗ったのですがどこに行くのかわかりません

BACK INTO ENGLISH

I got on the train last night but I don't know where to go

INTO JAPANESE

昨夜電車に乗りましたがどこに行けばいいのかわかりません

BACK INTO ENGLISH

I got on the train last night but I don't know where to go