How to Determine Internal Static IP on Hyper-V VM

I have a networking question that has me a bit stumped. I have a Windows 10 host running an Ubuntu guest in Hyper-V as a VM. I have an external virtual switch bridged to my computers wifi adapter so the guest VM is connected to the internet when my host machine is. Now, at my home network and my work network I am able to connect to SSH into the dynamically configured IP of the guest machine. When I am out at some place, like a local coffee shop, I am not able too. A little investigation makes me think this has something to do with the ISP configuration of my coffee shop.

Now, to get around this I figure I can set up an internal virtual switch, add that to my guest VM and then use that to SSH into my VM.

I know I need to set up a static IP for this to work, but I don't know enough about IP addresses to know which one I can use. Any advice on how I can determine this? Bonus points if you tell me how I can set up an internally resolved domain name so I can simple ssh into user@domainname instead of the IP address.