The heck you’re talking about? There’s a ton of free resources to learn the basics.
https://dotnet.microsoft.com/en-us/learn/csharp official Microsoft learning resources.
https://dotnettutorials.net/course/csharp-dot-net-tutorials/ for C# basics and .NET framework (which is backend standard).
For game engines you need specific tutorials in those engines.
Interestingly also Polish have the same sentence with the same meaning.