Welcome to BYC! Before you start incubating, do get a good quality thermometer and hygrometer. It's VERY important that you monitor the temperature and humidity in there. Once you have those items, get the incubator up and running and start tuning your settings, make sure it holds the correct temperature (99F for forced air and 101F for still air, measured on top of the eggs) and 45-50% humidity. I can't say how much water you will need in there as there are a number of things that influence it, like the humidity in the room you have the incubator in, etc.
I like to run a new incubator for 24 hours before setting eggs, to make sure everything's working as it should.
Regarding turning the eggs, minimum 3-5 times daily, but more is better. Good luck with your hatches!