Curt,

I'm sure Basil will have better answers, but I can provide a couple pointers to get started.

>how do I go about learning that "apt-get remove udrc-dkms" does something specific?

This is a really good break down of all the kinds of things apt-get can do and how todo them. 

https://www.tecmint.com/useful-basic-commands-of-apt-get-and-apt-cache-for-package-management/

>how do you remember all that stuff? 

You don't, unless you are using them all the time. (apt-get is pretty basic if you use the command line as the primary interface to linux, so it is a easy one.) But the more odd stuff, you remember there is something that does a thing and then you go look up how. At least that is how I do it, or you figure it out once and put it into a script, which is something Basil does.

>Where does a guy go to learn it and leave the evil world of windows behind?

My recommendation, setup a second box and try todo as much as  you can with it, but don't make it a binary decision immediately. At some point you'll figure out that you have stopped using Windows 90% of the time and you will have switched.

Good luck!
Kenny