You can create a vApp from a template stored in a catalog that you have access to. Permissions on catalogs are dictated by your role within the vDC. https://docs.vmware.com/en/VMware-Cloud-Director/10.2/VMware-Cloud-Director-Tenant-Portal-Guide/GUID-E1A79BB2-9BCA-4250-BDC2-3727C65F100A.html
Category: vApp
How to save a vApp template?
You can create a vApp template by saving an existing vApp to a catalog. https://docs.vmware.com/en/VMware-Cloud-Director/10.2/VMware-Cloud-Director-Tenant-Portal-Guide/GUID-344E4A32-5416-4941-8705-8EC1AD27638E.html?hWord=N4IghgNiBcIBYHsDuACALglBjATgUzDTxTBQDcBBAByvTwFsqJC8QBfIA
Add networks to a vApp?
Add a network to a vApp, making the network available to the VMs on the vApp. Direct or fenced connections are both possible. https://docs.vmware.com/en/VMware-Cloud-Director/10.2/VMware-Cloud-Director-Tenant-Portal-Guide/GUID-B95FB8AF-C428-4FCB-88DA-5DCA35B19B5A.html
How to add a VM to a vApp?
Organization administrators or vApp authors may add virtual machines to vApps. https://docs.vmware.com/en/VMware-Cloud-Director/10.2/VMware-Cloud-Director-Tenant-Portal-Guide/GUID-DD851141-B111-4618-99D9-B1C591D7827F.html
How to build a new vApp?
Users with the vApp Author role are able to create a new vApp rather than copying one from a template. https://docs.vmware.com/en/VMware-Cloud-Director/10.2/VMware-Cloud-Director-Tenant-Portal-Guide/GUID-19FD52A4-94B9-4001-8CE0-A50BD1F0D4A1.html