Help in creating a test lab environment for new equipment

Hi,
So I’m actually newbie at installing anything and recently we have ordered a Managed switch and Unifi Equipment. The problem is that after initial setup we were forced to use it on production and then problems happen haha.
If it’s possible to ask for advise about creating a separate network (physically too) to test new equipment before running in production.
My setup could be like this:
Wireless router (which is connected to the main LAN but with DHCP) then connect a test pfSense box then the managed switch then the UNIFI. Or hotspot a phone then use it as a WAN connection ? Thanks for the tips!