I would steer clear of the Gaussmarkov library simply because the pad sizes are way too small, there maybe a few things in there that are useful but on the whole the madbean library is way more usable.
I'd suggest removing all of the existing managed libraries on eagle and just using the madbean library until you are comfortable with how Eagle works and the process of generating a working board.
I'm at a point where I am comfortable generating my own components
Library.io is a really useful site if you need to generate new components
The AutoCAD Eagle forum is a useful resource
Again if anyone needs any pointers gimme a shout