Good! Tetsuma's nature is water/earth, so she actually knows a good bit to teach with.
They're going to be on 'pulling water out of things' for a while, though, just with increasingly big or difficult things. Then making waves in the water, once they find a lake. Then forming the water into a sort of funnel to drench things (great for putting out fires). The water clone, when his reserves and control are large enough.
(Tetsuma also has him working on chakra control - floating leaves over his palms, running up trees, standing on water, catching things without touching them, and so on. Plus more non-elemental chakra manipulation like genjutsu, and fighting hand-to-hand or with weapons.)