Windows 10 does not reach end of support until 2025. See https://learn.microsoft.com/en-us/lifecycle/products/windows-10-home-and-pro.
Regarding moving Plex to a new system, the basic approach is to install Plex Media Server on the new system, then copy the Plex Data Folder (database, etc.) from the old system to the new system.
There are guides to help with the process:
Move an Install to Another System
If you are moving to Linux, the Plex Linux FAQ has helpful information regarding running Plex on Linux and moving from another platform to Linux.
FAQ: Linux Tips
