Don’t skip meals, even if your schedule gets overloaded and you can’t eat until late at night. It’s better to eat something small than nothing at all.
Eight glasses of water a day is a good rule of thumb, but one athlete may sweat more than the other and will need more fluids. Do some self-evaluation and adjust. How thirsty do you become? How much do you sweat? Are you working out indoors or out?
If coffee is your normal drink in the morning and your body is used to it, then it shouldn’t be a problem. However, do not consume coffee with the thought that the caffeine will better fuel a workout.