Imbortant to note, the accent in japanese is not stressed like english or french, but pitched. So when you are listening for it in your duoligo, don’t listen for the syllable with attack, listen for places where the pitch goes up or down.
there are 4 patterns of pitch accent. A good explainer is Here, or on youtube from Dogen
みず is あたまだか, where the first mora is high, then the second one (and all the others would be) is low. You can hear the fall on the ず, where it geos from the starting pitch to a lower one