to drain or not to drain fresh water

All great posts btw. Newbie here living in S Texas. I guess its fine to do whatever choice you use. I used to pour Clorox down all our house drains once a month. Not any more for the past few years. I think Clorox can be a bit overused. Have had our Class A for three months now and I still drink the water from it. Others prefer bottle water (didn't now it had an expiration date). Now the big thing next for me is how to drain and fill the tank properly without the "OMG, Am I doing this correctly". Guess I need to take the plunge and suffer any consequences. And its time to really get into it including showers. I've used the water sparingly and used bottle water like the others in my family do. But I do want to drain the HW and refill so no probs later down the line. Later its the black water and gray tanks. Shaky I tell you being such a novice/newbie.