Bananas like well draining soil. I suggest cactus mix.
Avoid regular potting soils because they usually contain peat moss and retain water, causing root rot.

how often do you water it? how much water? do you have to wait till the soil is dry to water it?

watering depends on temperature. if your keeping your banana inside then you should probably water it with a good soaking twice a week. do not let the soil completely dry out whatever you do.