I installed Visual Studio Code and the extension of "Visual Studio Team Services". I pressed F1 and "team: login" and got the following error message.
(team) You must open a repository folder in order to use the Team Services extension.
How to create a repository folder using VSC? There are a lot of information about Git on VisualStudio.com(Visual Studio team services) but not TFVC.
Seems you want to use Visual Studio Code to connect a TFVC project by using Team Services extension for Visual Studio Code.
Make sure you are using version 1.116.0 or later, it provides support for the TFVC source control system!
Create your TFVC workspace
With TFVC, the extension uses information about the current workspace to determine how to connect to Team Services (or your Team Foundation Server). Workspaces can be created using the Visual Studio IDE, Eclipse or with the JetBrains IDEs (e.g, Android Studio, IntelliJ).
Note: At this time, you will need to have a local TFVC workspace already available on your local machine.
To learn more about the TFVC support, review this tutorial documentation or watch the overview video.
Besides, you need working on Team Foundation Server 2015 Update 2 (and later).