It is best to store your mushrooms in a fridge around 4°C if you want to keep them fresh for just a couple of days. If you’re looking for a longer period of storage, it is best to dry your mushrooms. Simply lay out your mushrooms on a grill or plate for a couple of days at room temperature. It is possible to dry them outside if it’s hot and dry.
Do not try to dry them in the oven. This does not work unless you have an oven that heats up below 30°C. But most ovens don’t, so just dry them in plain air.
Mushrooms can’t be frozen. Many people do it, and it’s not dangerous or anything, it’s just that the taste of your mushroom gets lost. Once defrosted, they just taste horrible. It is a waist of your money and mushrooms. Do not try it.