Hi @DRG
I believe from 9.7 or higher the ONTAP Simulator stopped supporting VMware ESX vSphere, and only supports VMware Workstation (Windows), VMware player or VMware Fusion
You likely will need to build a new ONTAP Simulator env using the ONTAP Simulator 9.7 OVA download on VMware Workstation (Windows), VMware Player or VMware Fusion. Alternatively, if you only have access to VMware ESX/Vsphere you can potentially do an ONTAP upgrade on the ONTAP cluster you setup using the 9.5 ONTAP Simulator image (but you would need to have an Support Sites account that can access ONTAP image software). There are a few external blogs/youtube videos walking folks through how to perform an ONTAP upgrade on the ONTAP Simulator.
To your question about running two nodes, suggest you take a look at Page 13 of the Installation Guide for ONTAP Simulator 9.7 - https://mysupport.netapp.com/api/tools-service/toolsbinary/simulate-ontap/download/Simulate_ONTAP_97_Installation_and_Setup_Guide.pdf
There is similar instructions about setting up two node Simulator cluster for 9.5 here (Starting Page 29) - https://mysupport.netapp.com/api/tools-service/toolsbinary/simulate-ontap/download/Simulate_ONTAP_9.5P6_Installation_and_Setup_Guide.pdf
The key thing to note is 1 OVA image is ONE ONTAP node.
Hope this helps point you in the right direction.