Vacuumed sealed hops and yeast are best stored in the freezer for long term storage. For just a couple of months the refrigerator is okay. DME can be stored cool and dry for years. LME should be refrigerated.
Depends on the heat temp at your area. Me got issues not putting dme in the fridge. It became hard like a rock. Now i vacume. And stick everything in the fridge
I agree with @sneezles61 do some double brew days. Who knows how long those kits have been on the shelf already. But if you cant do that keep the stuff refrigerated.