Getting started
It is important to understand that WG Tunnel is a VPN client application and not a VPN service provider. In short, this means that this application does not provide a VPN server for users to connect to by default. It is expected that the user either is hosting their own VPN server, or they have a VPN service provider.
If you are new to using VPNs and do not yet have a VPN service provider or VPN server, one of the easiest ways to get started is with a free VPN service provider like ProtonVPN.
Steps for getting a WireGuard config:
Create a new account on ProtonVPN's site.
Follow their tutorial on how to export a WireGuard configuration file.
On the main screen of WG Tunnel, click the floating action button and select "Add from file or zip".
Navigate to your newly downloaded WireGuard .conf configuration file and select it.
You are now ready to start using WG Tunnel as your Android VPN client.