Question: is the last wish the first witcher book

Answer: Yes, The Last Wish (Polish: Ostatnie życzenie) is the first (in its fictional chronology; published second in original Polish) of the two collections of short stories (the other being The Sword of Destiny) preceding the main Witcher Saga, written by Polish fantasy writer Andrzej Sapkowski. The first Polish edition was published in 1993, the first English edition was first published in 2007. The book has also been translated into several other languages.