Separate everything into lab and production, starting with your network. Test everything in your lab, then move it to production when you’ve ironed out the kinks.

So setup an isolated network in your router (pretty much all can do it these days), and test everything there.

Alternatively, build an isolated test environment in a virtualization solution, like ESXi or Proxmox - though these are both advanced skillsets (or at least not beginner). ESXi is easier to learn than Proxmox, and you should still be able to get a copy.