How much water should I add per watering? How ofte...

You don’t need to add much water at this stage of growth. I would say about a cups worth of water in total due to your pot size. Make sure to not overwater at this stage. Once you have watered the pot will become a little heavy. Wait until it become light weight again before watering. You will only end up having to water once every few days. No need to add nutrients at this moment in time. Wait until she is about 3-4 weeks old before you even think about feeding. When you do decide to start feeding use 1/4 the recommended dosage of whatever nutrients you are using and only increase if you start to notice deficiencies. I will be around if you need any more help. Good luck on your grow!