VPN Client-Server configuration - Working remotely with company VPN

Can you tell me. My ISP is connected to a netgear router, i have to connect my GL-ax1800 to that router.
I can put wire between the a netgear port to the Gl-ax1800. Should I put it in the WAN port on the Gl-ax1800 or a LAN port.

I want to start up a wireguard server on that setup and a wireguard client on my berly.

Can you tell me what else I need to do to the netgear router so I can do that?