No, you cannot purchase a SIM card directly from an Apple Store. However, Apple Stores often carry SIM cards from various carriers that can be activated with a new service plan. These SIM cards are usually available for specific carriers and regions, and their availability may vary from store to store. It's always a good idea to check with the Apple Store nearest to you to see if they carry the specific SIM card you need for your device and carrier. Alternatively, you can purchase a SIM card directly from your carrier or through their website.