`Newbie:UTP RJ45 cable
I am a newbie, so maybe this is a stupid question:
How can I connect my Wemos Mini to a cabled network? Can I do this using a USB2RJ45 module?
And are there standard drivers that support this? Do I have to use a specific brand/type so support is standard?
In short, you can't. It is generally possible -- it has been done as a hack, see http://hackaday.com/2016/04/01/ethernet-controller-discovered-in-the-esp8266/ -- but it's a rather advanced thing, and not very useful. If you need cabled ethernet, I would recommend using a RaspberryPi instead.