I have just installed windows 10 and wanted to give a try on windows universal desktop apps. With the installation of Visual Studio community version there were no templates for
If you are indeed "missing the templates" for Universal Windows apps for your VS 2015 installation on a Winodws 8.1 or Windows 10 development system, then you should make sure you actually have the UWP tools installed. They are not installed by default. You have to use the 'Custom' install option and select them.
You can do this after installation by going to Control Panel -> Programs and Features -> select Microsoft Visual Studio 2015 and hit Change, then Modify, and then make sure that you have checked the Tools and Windows SDK 10 option under Universal Windows App Development Tools. If not, you can check it here and install it. See Universal Windows apps in .NET
If you already have these installed, but they still don't work you can try the Repair option instead of Modify
BTW, I know you mentioned C#, but for anyone wanting to use C++, be sure to enable that as well--this is also not installed by default. See Setup Changes in Visual Studio 2015 Affecting C++ Developers and Developing for Windows 10 with Visual C++ 2015.