Hey alex335678 first up, Happy New Year! Also I don't work for Microsoft. This page https://support.microsoft.com/en-gb/help/4527875 shows under general questions:
https://support.microsoft.com/
Support for Windows Server 2008 and Windows Server 2008 R2 ends on January 14, 2020. https://www.microsoft.com/cloud-platform/windows-sql-server-2008.
Learn more here is:
https://www.microsoft.com/en-us/cloud-platform/windows-sql-server-2008
I'm not involved with replacing Win2008 but from everything I've read to date, you can migrate it to Azure (depends on your licensing from memory) or get off it. There is no easy answer to such work.
I've been involved with eradicating Win7 in our enterprise. Even that takes about 50 ppl globally slowly chipping away at it.
Good luck!