In this simulation, the SDDC has already been deployed. You will log into the VMware Cloud on AWS to configure Firewall Rules and then accessing the vCenter you will configure Content Libraries, create a Logical Network, create a Linux customization spec, deploy a virtual machine, and then convert that virtual machine to a template.
First I would like to suggest the great content provided by Andrea Siviero, Principal Architect, Global
Jennifer Schmidt, Consulting Architect, USA @ VMware in their Hands-On-Labs and their manual http://docs.hol.vmware.com/HOL-2019/hol-1987-01-hbd_pdf_en.pdf
I went through the process and here are the steps.