I can teach you how to manage xenserver from xen center, Xen-Orchestra Web Interface and xe command line stack.
I can enable ssh service on your xenserver to access terminal remotely.
If your xenserver is behind a router, I would configure port fordwarding or an openvpn in you server so that you can run xencenter on your local windows desktop and connect it to the server via vpn connetion.
I have worked with xenserver several times as virtualized infrastructure of network services like samba4 domain controller, pfsense firewall, dhpc, bind9 among others.
https://www.freelancer.com/projects/System-Admin/XenServer-Remote-Setup-support/
https://www.freelancer.com/projects/Linux/Install-citrix-existing-cloud-11668014/