hi, you dont feed until they need fed. depends how many weeks added feed there is in your peat mix. usually with a pre fed mix you can get all the way to the flowering stage with just water, but watch your leaves, if they need fed they will begin to go pale and yellow from the base. dont panic if this happens just begin feeding.
and dont water it all the time , wait until the pot feels light to lift up so it has dried out a bit between waterings. usually you shouldnt need to water more than once a week in the early days, as the plant gets big this can increase to every other day. depends on how hot your environment is to though