Wireguard setup guidance requested

I want to setup my ER707M2 as a wireguard server so I can connect to my home network while travelling. I'm reading the documentation and need a little clarification, mostly on terminology. I'm used to using an SSL VPN on a Sophos firewall.

• Is the client's VPN IP address predefined on the user name?
• What will the client be using for DNS? which may be related to the next point
• For the "client access" setting when setting up the server, I have "home network only" or "internet and home network". Which choice only pushes traffic for my home network over the VPN, but directs all other traffic over the base network connection? Or does WireGuard not do that?

Thanks for any pointers. And before anyone says it, yes, I am aware of TailScale.