OmniSharp (VS Code extension for C#) has been discontinued and there is no replacement yet. Besides, Microsoft purpusefully sabotaged OmniSharp to make it so unusable that it forces people to use Visual Studio, so even if a beginner on Linux would decide to try C# with a discontinued product they would only face difficulties and a basically horrendous mostly broken experience. .NET on Linux is non existent without Rider and there is no way to sugarcoat this fact. It's sad how ignorant some people are about this and keep peddling untruths about C# that it is well supported on Linux when it isn't.