If you haven't been there already, may I suggest this link:
I found suggestions there a helpfull for using Linux Questions as a resource.
In fact the title bar link to "Tutorials" will lead you to this and other
useful information. But to your question.
Generally, coming from a windows or dos background you have a large amount to learn.
Recall that linux is aimed at being a freely available "Unix-Like" system,
and Unix has grown and developed over time since the Ninteen-Seventies...(30+yrs).
Fortunately, you won't need to know all of it at once.
Since you already have working distributions installed, your're
well on the road. As has been suggested on LQ before, be prepared to read,
There are several books available at your local Public Library or for sale at
bookstores that you may find helpful, but to get your own
list going, try reading this thread:
Also, if you go all the way to the bottom of the thread, you'll
find a list of similar threads.
Google is your friend here. Unlike other operating systems the
beginning problem with linux for me was not a lack of information,
but rather so many and such diverse viewpoints leading to the same solution
that it was bewildering at first. But hang in there
it's just a learning curve