Ideally, defrost the squid for several hours in the refrigerator, but if there is very little time, immediately throw it into boiling salted water. In this case, it will both defrost and prepare. In any case, do not defrost in a microwave oven or in warm water. This will make seafood look like porridge.
So, boil the squid in boiling salted water for 3-5 minutes. No more, otherwise it will become rubbery.