The full complement of configuration files is available here.
Please note: aside from getting the correct configs, you must remember to assign the --testnet-magic <natural> flag instead of --mainnet whenever needed.
Please note: for your nodes to communicate correctly you will need to add the node port you assign during the build, both to firewalld and OCI Security List. This is similar to what you did for ssh here.
Success: once you are done with your first node, rinse and repeat for the others.