I installed Team Foundation Server Express 2015 and I am able to build my code but there is no release button so I don't know how else to deploy my code. I tried to install a release management server and a release management agent but I still don't see any release options on the Team Foundation Server. Does anybody know why I'm not even able to see the release hub and how to fix it?
Release Management features is integrated into the RELEASE hub in TFS web access of TFS 2015 Update 2 and above.
Instead of TFS express, I would like to suggest you use Visual Studio Team Service. The First 5 users are FREE for VSTS, and you can test most features on VSTS.
Installing Release Management's server and client is an old way. With this way, TFS is not a mandatory requirement. Release Management can be used in a standalone mode to deploy applications. You won't see RELEASE hub in TFS web access.
More details of Release Management, please check: https://www.visualstudio.com/en-us/docs/release/previous-version/release-management-overview