We have converted a porch into a panty & never open the outside door but the area around the door has gotton wet. How can we repair this

Have you weather-proofed the inside and outside of the outside door? Did you insulate before you put up the sheetrock when you build the pantry? Or, if you want to make it permanent, why not remove the door, insulate and then either shake or put siding, whatever the outside of your house is.