If you decide to proceed with a symbolic gift, several retailers offer packages that include certificates and star-finding tools: Policies and Frequently Asked Questions - NASA
If you are looking to "buy a star" as a symbolic gift, you can use private commercial services. Here is how that process works and what to expect. How Symbolic Star Naming Works
: While reputable private registries promise not to sell the same star twice within their system, another company could easily sell the "naming rights" for that same star to someone else.
: Most services use official databases (like those from the European Space Agency) to ensure the coordinates they give you correspond to a real, existing star in the sky. Popular Symbolic Gift Options