On the Team Explorer, Click on the icon highlighted in the screen-shot below and then click on Manage Connections. Select “Connect to a Project” from the Menu.
Manage Connections is also available under the Team menu in Visual Studio.
If your Team Foundation Server is not already added then click on the “Add TFS Server” link and you’ll need to enter the TFS URL and click on Add.
You may need to enter your credentials in the pop-up window. The list below shows the Test Project, select it and click on Connect.
Finally you can map the TFS Server path to your Workspace Project i.e. Physical folder on your machine as shown below: