Water only when the pot is light. Feel it when you water to see how that feels heavy. When it feels light to very light, water then. after doing it for awhile it becomes natural and second nature.
It's important cuz you need the soil to dry out so the roots grow in search for more water and nutrients.
if your using soil with nutes in it like MG or organic dont keep feeding it as there stuff already in the soil. other then that just give it a light feeding every week or two (water any other time only).
also, how much do you water when you water??? 500ml?? 1L??
you'll be fine...........just dont over water or over fert it will kill you fast.