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