hard to say about indica or sativa this early, best indicators are the broadness of your leaves.
You will have to wait till you flower before you can sex, maybe 5-12 days into flowering, post some pics, im sure lots of people here will help you tell whether or not you scored a female.
You can start flowering whenever you like, depends how much vertical height you have to play around with, expect to double your height + or - depending on the strain and various other enviromental factors. Personally, on your first grow, I would flower at 8 inches or so as it should just be considered a learning curve anyways.