For this sample, we've already generated the server and client stubs from helloworld.proto.
Example projects in this directory depend on the Grpc and Google.Protobuf NuGet packages which have been already added to the project for you.
You can also build the example directly using Visual Studio 2017, but it's not a requirement.
From the examples/csharp/Helloworld
directory:
dotnet build Greeter.sln
Run the server
> cd GreeterServer > dotnet run -f netcoreapp2.1
Run the client
> cd GreeterClient > dotnet run -f netcoreapp2.1
You can find a more detailed tutorial about Grpc in gRPC Basics: C#