You can use the Windows Compatibility Pack (article, nuget) for .NET Core which gives you access to a lot of Windows-only APIs but restricts your app to running only on Windows, probably not something you're worried about. This compatibility pack is also known as platform extensions. With this you would need to learn how to use the classes in the System.Management
namespace (API Ref, example code 1, example code 2). Keep exploring the API for examples.
Additionally, it looks like there is a newer cross-platform open-source system similar to CIM made by Microsoft. Though apparently not everything available in WMI is available with this, so your mileage will vary: https://www.nuget.org/packages/Microsoft.Management/ and https://www.nuget.org/packages/Microsoft.Management.Infrastructure/
Hope this helps.