Use a supported version of SQL Server
Microsoft releases a new version of SQL Server roughly every two years. Although you may not need any of the features provided in the new version, it is important to upgrade to a version of SQL Server that is still under support in order to obtain security fixes, especially if your SQL Server is exposed to the Internet.
If a security vulnerability is discovered in a version of SQL Server that is no longer under support, Microsoft will probably not provide a patch to fix the vulnerability, and you can be sure hackers will attempt to exploit it.
Microsoft offers you the ability to buy Extended Security Support, but you must purchase these before the security vulnerability is found and even extended support will eventually no longer be offered.
SQL Statements
Run this SQL to find the version of SQL Server you are running:
SELECT @@version as FullVersion, SERVERPROPERTY('ProductLevel') as ServicePack, SERVERPROPERTY('ProductVersion') as VersionNumber;
Additional Resources:
Support for SQL Server 2014 ends July 9, 2024