Store your grain in an air tight container and keep in a dry environment. Refridgerators and freezers should not be used for storing grains as the grains contain a lot of moisture. Your gains should remain fresh for months after milling when store properly.
It’s ok to store hops in the fridge, but it’s better to store them in the freezer if you intend to keep them for long periods of time.
Dry yeast is ok to keep at room temperature for an extended period of time, but refridgeration is required if you intend to keep them to their expiration date which can be 1 to 2 years.
Liquid yeast can survive for a few days at room temperature, but it’s best to store them in the fridge if you expect them to be viable up to their expiration date.