YOU SAID:

My dad left to buy milk but got lost.

INTO JAPANESE

父は牛乳を買いに行ったが、道に迷った。

BACK INTO ENGLISH

My father went to buy milk, but lost his way.

INTO JAPANESE

父は牛乳を買いに行きましたが、道に迷いました。

BACK INTO ENGLISH

My father went to buy milk, but lost his way.