YOU SAID:

I went to the park with a baby and left with no baby

INTO JAPANESE

私は赤ちゃんと一緒に公園に行き、赤ちゃんと一緒にいなくなった

BACK INTO ENGLISH

I went to the park with my baby and stayed with my baby

INTO JAPANESE

私は赤ちゃんと一緒に公園に行き、私の赤ん坊と一緒に泊まった

BACK INTO ENGLISH

I went to the park with my baby and stayed with my baby