You can start with cold water or hot (160-170F), although if you bag the grain there is a slight chance of burning the bag if you let it sit in the kettle during the heating. I've only done that once.
Water: spring water, random trace minerals will help the yeast grow.
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"
"I would like to die on Mars, just not on impact." Elon Musk