Start at the gateway
The included gateway installer targets Ubuntu and Debian. If your home host is a Mac, use a Linux virtual machine with appropriate bridged networking, a reserved local address and a reachable public endpoint. A home setup exits through your home internet connection.
Give each device its own identity
Use a unique WireGuard key pair and peer configuration for every device. Keep private keys on their intended devices. The account portal records public-key requests; the operator still needs to apply each real gateway peer.
Test from outside home Wi-Fi
A local test cannot prove your router is reachable from the internet. Check a recent handshake over mobile data, then verify the intended external address, DNS and IPv6 behavior. Keep the home host and its VM awake when access is needed.