In order to use a WCF service, you will need to create a WCF client proxy.
In Visual Studio, you would right-click on the project and pick the "Add Service Reference" from the context menu. Type in the URL you want to connect to, and if that service is running, you should get a client proxy file generated for you.
This file will typically contain a class called MyService**Client** - you can instantiate that class, and you should see all the available methods on that client class at your disposal.
If you don't want to add a service reference in Visual Studio, you can achieve the same result by executing the svcutil.exe
command line tool - this will also generate all the necessary files for your client proxy class for you.
Marc
UPDATE:
if you want to initialize a client proxy at runtime, you can definitely do that - you'll need to decide which binding to use (transport protocol), and which address to connect to, and then you can do:
BasicHttpBinding binding = new BasicHttpBinding();
EndpointAddress address = new EndpointAddress("http://localhost:8888/MyService");
MyServiceClient serviceClient = new MyServiceClient(binding, address);
But even in this case, you need to have imported and created the proxy client first, by using the "Add Service Reference" or svcutil.exe tools.