I am not a tech person, all of this stuff is very new to me, so I have many questions.
I am trying to run the latest version of FreedomBox in the latest version of VirtualBox on an Ubuntu 18.04.4 desktop computer (computer A). I will continue using this computer for other purposes, it will not be dedicated to just FreedomBox.
Also behind my router I have another computer (computer B) running an Ubuntu server with the latest version of Nextcloud on it. (Someone smart set that up for me, but that person is no longer around for me to get help.) It runs great, I can access the Nextcloud server either from within my home network, or over the internet outside my home network.
I want to install FreedomBox in Virtualbox on computer A.
I don’t know which settings to go with on the router so that I can access FreedomBox both from within my home network, and also over the internet from outside my home network, without messing up how things work for my Nextcloud setup.
Despite all the reading I’ve done, the whole thing about port forwarding and firewalls and domains and certificates, etc., is all extremely bewildering to me.
What should I do on my router to accomplish what I describe above?
Secondary question: Do you know of any dumbed down documentation about port forwarding and firewalls, how to manage them and the strategy to follow, why I need a certificate, etc.? Everything I’ve looked up landed me in very deep water after just a few paragraphs.