HI Todd, the QQ190 main electronics have a special coating that makes them water resistant. If you are flying in very wet conditions, we recommend spraying down the electronics with corrosion x, which can help to waterproof things on top of what has already been done in the factory.
A damp rag can be used to clean the carbon. If you do get the electronics wet, the best thing to do is to let it dry completely before plugging it in.
I typically like to clean my quads with isopropyl alcohol, Q-tips, and a tooth brush, but others might want to chime in to see what works well for them.
Also, you will at some point want to make sure to lubricate your motor bearings, especially if flying in dusty, wet or otherwise adverse conditions.
Let me know if that helps to answer your questions!