When your spawn arrives unbox it right away and check over.
If it has broken up during shipping ( it will be all mixed up and will look like bare seeds).
Stand the bag up and sit somewhere dark around 20deg to recover for 1-2 days. (Some will grow back thicker and clearer than others, not all mycelium is/looks the same).
After this, store the bag in the fridge at 1-4 deg for most types and they will be fine for 4-8 weeks.
Some types like, Pink Oyster, Straw Paddy, Wood Ear can only be stored at 9-11 deg, colder than this and they will start to slowly die within 3-4 weeks, these warmer types we suggest using right away within 1-2 weeks of arriving.