If you have multiple user licenses, you'll need to assign permissions to a project.
Typically, you would use the built-in interface but due to some limitations imposed by Team Foundation server, you'll need to use the Control Panel to manage your users.
Perform the following steps to add a user to a project:
2. If you have multiple projects, select the project from the drop-down menu.
4. Check the desired members options and then click on the "Save" button to add the user.