Kiddush is the first ritual carried out at the Shabbat table. It is best, according to the rabbis, to make Kiddush over wine.
Rabbi Shimon bar Yochi (one of Rabbi Akiva’s top students) says if one cannot afford to buy both festive foods to celebrate Shabbat day and wine for the evening Kiddush, he should buy the wine (Mechilta).
Rabbi Eliezer ben Hyrcanus Hagadol says one who makes Kiddush over wine is privileged for a long life in this world and life in the World to Come (Pirkei d’Rabbi Eliezer, chap. 18). According to Midrash Maaseh Torah, among the six actions that will bring reward in this world and better reward in the World to Come is reciting Kiddush over wine. In a story of Rabbi Zakai recorded in the Talmud, he tells his disciples he has been blessed with a long life because, among other things, his mother sold her hat in order to afford wine for Shabbat (Megillah 27b).
Can you use grape juice instead of wine? According to the Talmud, “A person may squeeze out a cluster of grapes and recite Kiddush over the juice” (Baba Batra 97a).