You should install the Xamarin tools in your VS. This will take a lot of time. You might want to consider doing this one evening before leaving work.
If Visual Studio 2015 is installed on your computer, please follow https://msdn.microsoft.com/en-us/library/mt613162.aspx .
If you have Visual Studio 2017 please follow below:
Xamarin can be installed as part of a new Visual Studio installation. To achieve this, use the following steps:
Download Visual Studio Community, Visual Studio Professional, or Visual Studio Enterprise from the Visual Studio page (download links are provided at the bottom).
Double-click the downloaded package to start installation.
Select the Mobile development with .NET workload from the installation screen:
4. While Mobile development with .NET is selected, have a look at the Summary panel on the right. Here, you can deselect mobile development options that you do not want to install. By default, all options shown in the following screenshot are installed (Xamarin Workbooks, Xamarin Profiler, Xamarin Remoted Simulator, Android NDK, Android SDK, Java SE Development Kit, Google Android Emulator, F# support, and Intel HAXM):
5. When you are ready to begin Visual Studio installation, click the Install button in the lower left-hand corner:
Depending on which edition of Visual Studio you are installing, the installation process can take a long time to complete. You can use the progress bars to monitor the installation:
6. When Visual Studio installation has completed, click the Launch button to start Visual Studio: