you need to figure out what VLANs you need and how the communication (firewall rules) between them should work or not work. Which devices are connecting to your services/proxmox host from which VLANs?
To actually answer your question, if you want to figure it out try it in a tested lab setting or do this when you have time. I spent quite some time troubleshooting why certain firewall rules don’t work as expected,
you need to figure out what VLANs you need and how the communication (firewall rules) between them should work or not work. Which devices are connecting to your services/proxmox host from which VLANs? To actually answer your question, if you want to figure it out try it in a tested lab setting or do this when you have time. I spent quite some time troubleshooting why certain firewall rules don’t work as expected,