Hi Becky,

The only constraint for TFS Express is: 5 developers or less. As soon as your development requires a six'th person to access TFS, you need to migrate to the regular TFS version.

Install TFS Express on any server you have access too and be sure to test the installation with a MGCSTK (Magic) license. You cannot test it with Single User edition.

You'll need (on every machine where you want TFS access from Magic) an installation of MSSCCI Provider for TFS 32-Bit).

Now for me its years ago that I did such an installation so I cannot tell much about the versions you should choose. Following seems to be the latest MSSCCI Provider for TFS:
https://marketplace.visualstudio.com/items?itemName=TFSPowerToolsTeam.MicrosoftVisualStudioTeamFoundationServer20132015M

That supports Microsoft Visual Studio Team Foundation Server 2005, 2008, 2010, 2012, or 2013. Thats not the latest version of TFS I suppose so if it works with that ... I dont know.

You also need to check re the TFS source repository requirements for Magic. It needs to be server workspaces and you need to set that flag which dis-allows multiple checkouts, ...

Good luck :)

Andreas

P.S.: You would be better off with a cloud installation of TFS (Azure DevOps)