How is water changing state during evaporation and condensation? Does it start as a solid, liquid or gas? What does it become?
It is changing between its liquid and vapor states. Evaporation is what we call the transition from liquid to vapor. Condensation is what we call the transition from vapor to liquid.
The “states” of matter are usually solid, liquid and vapor (or gas). In some particular circumstances we also have unique states like plasmas (fully-ionized homogeneous high-temperature gaseous mixtures). The terms we use to describe a change from one to the other are simply descriptive nouns.
In addition to the liquid/vapor changes discussed, water also can change phase from solid to liquid (melting), liquid to solid (freezing) and a direct change from solid to vapor (sublimation).