more course en c#

Question

Have finished the c# course and then ?

Answer 1

Get familiar with Linq. It's one of the most useful features of c# in my opinion. The microsoft docs are a great source of information to learn about the usage of each function.
https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/concepts/linq/

Try to solidify your knowledge by solving programming challenges in C#. You can find a lot of them in SoloLearn too.